Reusable blocks in config.yml

[mimecine]

I am working on a simple page builder in Sveltia. It's easy enough to make a list of types, but when you want to get a bit fancier and have blocks inside blocks it will get tedious quickly.
It would be great to be able to reference pre-defined types somehow.
I imagine something like

- label: "Homepage Sections"
  name: "homepage_sections"
  file: "src/_data/homepage_sections.json"
  description: "Sections to be displayed on the homepage."
  editor:
  fields:
    - label: "Sections"
      name: sections
      widget: list
      collapsed: false
      types:
        -typeref: hero
        -typeref: carousel
        -typeref: post
        - ...

and

-typedefs:
  - label: Hero
    name: hero
    widget: object
    summary: '{{fields.title}}'
    fields:
      - { label: Image, name: image, widget: image, required: false }
      - { label: "Image Credit", name: credit, widget: string, required: false }
  - label: Carousel
    name: carousel
    widget: object
    - ...

[kyoshino]

I think it’s possible to implement this feature, but after 1.0. It’s one of the top-voted features of Decap:

• Allow reusable field group definitions in config file decaporg/decap-cms#1342

[kyoshino]

At this point, it would be easier to generate a JSON config or manually initialize the CMS using JavaScript (as you’ve already found in #451).

[kyoshino]

Also, as discussed in the Decap issue, YAML provides the native alias feature to make it work.

[mimecine]

Just started fiddling with YAML aliases. We are not friends yet.

[mimecine]

I just added the JSON schema for config.yml and wonder if it's possible to add a "definitions/typedefs/aliases" keyword where one can store YAML aliases? Obviously ignorable for now, but well, aesthetics and papercut problems...
And if there is a solution to externalize definitions it would be highly welcome, though I think I read you telling me it wasn't possible.