A couple weeks ago, I had a random thought of "what if there was a feat chain that let Eidolons dip into archetypes?" I'm not sure what levels it would be, but maybe somewhat in line with the spellcasting Eidolon chain? Like, at 2nd level you can take a Level 2 Dedication Feat, at level 8 you can take a Level 4 or lower Archetype feat for the dedication feat your Eidolon has taken, not sure what the specifics would be.

Are there any majorly broken options with this? Any interesting synergies? Or concepts that just seem cool? I really haven't thought too much about it beyond the surface level of "I wonder what this would be like", so I'm sure there's plenty to think of still.