With the latest PanelApp alpha I'd say its time to get concrete here.

Again assuming worst (best?) case and a mid 2025 MorphOS 3.20 release this should be in there:
- add an "Ambient.library" that will give access to prefs files (currently in PanelApp), bookmarks, open listers and so on
- make Prefspanes work as external classes and move at least the Panel one to it
- expand AppWindow/AppMessage so dragging can be monitored by non Ambient windows

Depending one timing this may be in 3.20 or get pushed to 3.22 (but will be done one way or the other):
- move all other Prefspanes into external classes
- allow subclassing Listers
- make search results a proper Lister (subclass)

Everything else mentioned here is considered optional and might or might not be addessed later on.