diff --git a/AGENTS.md b/AGENTS.md
index d67458f..24b94c3 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -11,7 +11,7 @@
 ## Build, Test, and Development Commands
 - Build workspace: `cargo build --workspace`
 - Run all tests: `cargo test --workspace`
-- Format (check): `cargo fmt --all -- --check` | Fix: `cargo fmt --all`
+- Format (check): `cargo +stable fmt --all -- --check` | Fix: `cargo +stable fmt --all`
 - Lint: `cargo clippy -p schemaview -p linkml_runtime -p linkml_tools -p linkml_runtime_python -p linkml_wasm --all-targets --all-features -- -D warnings --no-deps` (excludes autogenerated `linkml_meta`)
 - Run a CLI (example):
   - Validate: `cargo run -p linkml_tools --bin linkml-validate -- src/runtime/tests/data/schema.yaml Person src/runtime/tests/data/person_valid.yaml`
diff --git a/src/metamodel/src/lib.rs b/src/metamodel/src/lib.rs
index 25755e7..1a1e1d8 100644
--- a/src/metamodel/src/lib.rs
+++ b/src/metamodel/src/lib.rs
@@ -8200,176 +8200,176 @@ impl<'py> FromPyObject<'py> for Box<AnonymousSlotExpression> {
 #[cfg_attr(feature = "pyo3", pyclass(subclass, get_all, set_all))]
 #[derive(Merge)]
 pub struct SlotDefinition {
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub singular_name: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub domain: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub slot_uri: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub array: Option<ArrayExpression>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub inherited: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub readonly: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub ifabsent: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub list_elements_unique: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub list_elements_ordered: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub shared: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub key: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub identifier: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub designates_type: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub alias: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub owner: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub domain_of: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub subproperty_of: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub symmetric: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub reflexive: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub locally_reflexive: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub irreflexive: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub asymmetric: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub transitive: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub inverse: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub is_class_field: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub transitive_form_of: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub reflexive_transitive_form_of: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub role: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub is_usage_slot: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub usage_slot_name: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub relational_role: Option<RelationalRoleEnum>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub slot_group: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub is_grouping_slot: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub path_rule: Option<Box<PathExpression>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub disjoint_with: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub children_are_mutually_disjoint: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub union_of: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(deserialize_with = "serde_utils::deserialize_inlined_dict_map_optional")
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub type_mappings: Option<HashMap<String, TypeMapping>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub range: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub range_expression: Option<Box<AnonymousClassExpression>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub enum_range: Option<EnumExpressionOrSubtype>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub bindings: Option<Vec<EnumBinding>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub required: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub recommended: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub multivalued: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub inlined: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub inlined_as_list: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub minimum_value: Option<Anything>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub maximum_value: Option<Anything>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub pattern: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub structured_pattern: Option<PatternExpression>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub unit: Option<UnitOfMeasure>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub implicit_prefix: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub value_presence: Option<PresenceEnum>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub equals_string: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8378,56 +8378,56 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub equals_string_in: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub equals_number: Option<isize>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub equals_expression: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub exact_cardinality: Option<isize>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub minimum_cardinality: Option<isize>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub maximum_cardinality: Option<isize>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub has_member: Option<Box<AnonymousSlotExpression>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub all_members: Option<Box<AnonymousSlotExpression>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub none_of: Option<Vec<Box<AnonymousSlotExpression>>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub exactly_one_of: Option<Vec<Box<AnonymousSlotExpression>>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub any_of: Option<Vec<Box<AnonymousSlotExpression>>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub all_of: Option<Vec<Box<AnonymousSlotExpression>>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub is_a: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     #[cfg_attr(feature = "serde", serde(alias = "abstract"))]
     pub abstract_: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub mixin: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub mixins: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub apply_to: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8436,12 +8436,12 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub values_from: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub string_serialization: Option<String>,
     #[merge(skip)]
     pub name: String,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8450,23 +8450,23 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub id_prefixes: Option<Vec<ncname>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub id_prefixes_are_closed: Option<bool>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub definition_uri: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(deserialize_with = "serde_utils::deserialize_inlined_dict_map_optional")
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub local_names: Option<HashMap<String, LocalName>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub conforms_to: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8475,7 +8475,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub implements: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8484,37 +8484,37 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub instantiates: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(deserialize_with = "serde_utils::deserialize_inlined_dict_map_optional")
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub extensions: Option<HashMap<String, ExtensionOrSubtype>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(deserialize_with = "serde_utils::deserialize_inlined_dict_map_optional")
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub annotations: Option<HashMap<String, Annotation>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub description: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(deserialize_with = "serde_utils::deserialize_inlined_dict_map_optional")
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub alt_descriptions: Option<HashMap<String, AltDescription>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub title: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub deprecated: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8523,7 +8523,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub todos: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8532,7 +8532,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub notes: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8541,25 +8541,25 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub comments: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub examples: Option<Vec<Example>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub in_subset: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub from_schema: Option<uri>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub imported_from: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub source: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub in_language: Option<String>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8568,13 +8568,13 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub see_also: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub deprecated_element_has_exact_replacement: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub deprecated_element_has_possible_replacement: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8583,10 +8583,10 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub aliases: Option<Vec<String>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub structured_aliases: Option<Vec<StructuredAlias>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8595,7 +8595,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub mappings: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8604,7 +8604,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub exact_mappings: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8613,7 +8613,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub close_mappings: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8622,7 +8622,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub related_mappings: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8631,7 +8631,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub narrow_mappings: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8640,10 +8640,10 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub broad_mappings: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub created_by: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8652,22 +8652,22 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub contributors: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub created_on: Option<NaiveDateTime>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub last_updated_on: Option<NaiveDateTime>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub modified_by: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub status: Option<uriorcurie>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(feature = "serde", serde(default))]
     pub rank: Option<isize>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -8676,7 +8676,7 @@ pub struct SlotDefinition {
     )]
     #[cfg_attr(feature = "serde", serde(default))]
     pub categories: Option<Vec<uriorcurie>>,
-    #[merge(strategy = merge::option::overwrite_none)]
+    #[merge(strategy = overwrite_except_none)]
     #[cfg_attr(
         feature = "serde",
         serde(
@@ -12869,3 +12869,10 @@ impl serde_utils::InlinedPair for TypeMapping {
         }
     }
 }
+
+/// Overwrite `left` with `right` unless `right` is `None`.
+fn overwrite_except_none<T>(left: &mut Option<T>, right: Option<T>) {
+    if right.is_some() {
+        *left = right;
+    }
+}
diff --git a/src/schemaview/src/schemaview.rs b/src/schemaview/src/schemaview.rs
index 4a59bfe..0728bbc 100644
--- a/src/schemaview/src/schemaview.rs
+++ b/src/schemaview/src/schemaview.rs
@@ -228,6 +228,12 @@ impl SchemaView {
         self.data.schema_definitions.iter()
     }
 
+    /// Returns a converter built from every schema loaded into this view.
+    ///
+    /// Note that prefix collisions across schemas will resolve to whichever
+    /// expansion appears last; avoid this helper if you expect conflicting
+    /// CURIE mappings and instead use `converter_for_schema` with a specific
+    /// schema URI.
     pub fn converter(&self) -> Converter {
         converter_from_schemas(self.data.schema_definitions.values())
     }
diff --git a/src/schemaview/src/slotview.rs b/src/schemaview/src/slotview.rs
index d432a38..1d1c372 100644
--- a/src/schemaview/src/slotview.rs
+++ b/src/schemaview/src/slotview.rs
@@ -53,22 +53,32 @@ impl RangeInfo {
         e: &SlotExpressionOrSubtype,
         slotview: &SlotView,
     ) -> Option<ClassView> {
-        let conv = slotview.sv.converter_for_schema(&slotview.schema_uri)?;
         e.range().and_then(|r| {
+            if let Some(conv) = slotview.sv.converter_for_schema(&slotview.schema_uri) {
+                if let Ok(Some(cv)) = slotview.sv.get_class(&Identifier::new(r), conv) {
+                    return Some(cv);
+                }
+            }
+            let conv = slotview.sv.converter();
             slotview
                 .sv
-                .get_class(&Identifier::new(r), conv)
+                .get_class(&Identifier::new(r), &conv)
                 .ok()
                 .flatten()
         })
     }
 
     fn determine_range_enum(e: &SlotExpressionOrSubtype, slotview: &SlotView) -> Option<EnumView> {
-        let conv = slotview.sv.converter_for_schema(&slotview.schema_uri)?;
         e.range().and_then(|r| {
+            if let Some(conv) = slotview.sv.converter_for_schema(&slotview.schema_uri) {
+                if let Ok(Some(ev)) = slotview.sv.get_enum(&Identifier::new(r), conv) {
+                    return Some(ev);
+                }
+            }
+            let conv = slotview.sv.converter();
             slotview
                 .sv
-                .get_enum(&Identifier::new(r), conv)
+                .get_enum(&Identifier::new(r), &conv)
                 .ok()
                 .flatten()
         })
diff --git a/src/schemaview/tests/data/slot_usage_base.yaml b/src/schemaview/tests/data/slot_usage_base.yaml
new file mode 100644
index 0000000..3e71135
--- /dev/null
+++ b/src/schemaview/tests/data/slot_usage_base.yaml
@@ -0,0 +1,15 @@
+id: http://example.org/base
+name: base
+prefixes:
+  base: http://example.org/base/
+default_prefix: base
+default_range: string
+
+classes:
+  BaseThing:
+    slots:
+      - shared_slot
+
+slots:
+  shared_slot:
+    range: string
diff --git a/src/schemaview/tests/data/slot_usage_specialized.yaml b/src/schemaview/tests/data/slot_usage_specialized.yaml
new file mode 100644
index 0000000..8d07a5c
--- /dev/null
+++ b/src/schemaview/tests/data/slot_usage_specialized.yaml
@@ -0,0 +1,26 @@
+id: http://example.org/specialized
+name: specialized
+prefixes:
+  specialized: http://example.org/specialized/
+  base: http://example.org/base/
+default_prefix: specialized
+default_range: string
+imports:
+  - http://example.org/base
+
+classes:
+  TargetClass:
+    slots:
+      - target_slot
+
+  SpecializedThing:
+    is_a: base:BaseThing
+    slots:
+      - shared_slot
+    slot_usage:
+      shared_slot:
+        range: specialized:TargetClass
+
+slots:
+  target_slot:
+    range: string
diff --git a/src/schemaview/tests/slot_view.rs b/src/schemaview/tests/slot_view.rs
index 084f7be..de2c3f8 100644
--- a/src/schemaview/tests/slot_view.rs
+++ b/src/schemaview/tests/slot_view.rs
@@ -41,3 +41,47 @@ fn slot_lookup_and_class_slots() {
     assert_eq!(map.get("symbol"), Some(&1usize));
     assert_eq!(map.get("exact mappings"), Some(&2usize));
 }
+
+#[test]
+fn slot_usage_overrides_range_across_schemas() {
+    let base_schema = from_yaml(Path::new(&data_path("slot_usage_base.yaml"))).unwrap();
+    let specialized_schema =
+        from_yaml(Path::new(&data_path("slot_usage_specialized.yaml"))).unwrap();
+
+    let mut sv = SchemaView::new();
+    sv.add_schema(base_schema.clone()).unwrap();
+    sv.add_schema(specialized_schema.clone()).unwrap();
+
+    let conv = converter_from_schemas([&base_schema, &specialized_schema]);
+
+    let base_class = sv
+        .get_class(&Identifier::new("base:BaseThing"), &conv)
+        .unwrap()
+        .unwrap();
+    let base_slot = base_class
+        .slots()
+        .iter()
+        .find(|s| s.name == "shared_slot")
+        .expect("shared_slot not found");
+
+    assert_eq!(base_slot.definition().range.as_deref(), Some("string"));
+
+    let class = sv
+        .get_class(&Identifier::new("specialized:SpecializedThing"), &conv)
+        .unwrap()
+        .unwrap();
+    let slot = class
+        .slots()
+        .iter()
+        .find(|s| s.name == "shared_slot")
+        .expect("shared_slot not found");
+
+    assert_eq!(
+        slot.definition().range.as_deref(),
+        Some("specialized:TargetClass")
+    );
+    assert_eq!(
+        slot.get_range_class().map(|cv| cv.name().to_string()),
+        Some("TargetClass".to_string())
+    );
+}