simple_form @as doesn't override default form value

[gregors]

Environment

• Elixir version: 1.18.4
• Phoenix version: 1.7.21
• Operating system: Linux

Actual behavior

When using .simple_form, If I add a for={@form} as={:test_form} I expect that on submit I would see the params submitted under "test_form" however it is ignored and continues to use the default struct name in @form. However, if I set the options on the to_form call to_form(changeset, [as: "test_form"]) it does work fine. I'm curious if this had something to do with #5901?

Expected behavior

:as should override the default form parameter name