The structures, that are not automatically collapsed under an API name, should be collapsible under a folder/grouping
Just structures, or also other elements? I often find it annoying that the referenced actions come after the local actions, which can't be collapsed (as a single unit) either. Iirc, this was introduced in version 9 or 10.
I suppose the collapse pattern could be applied to all elements to keep the UX consistent.
I agree that the referenced actions that are shown after local actions is a real inconvenience.