Snippets/components in form definitions
It would be useful if the Form framework did support snippets/components. These could then be referenced in a regular form definition and would be inserted on the fly as soon as the form is built.
Obviously some kind of parameter support would be necessary here to make it easy to e.g. set the name for a form field provided by a snippet.
Maybe this could be achieved with #84204 and YAML anchors/references.