I think this would make a fun and cool new research field for the 2E alchemist.
I have some ideas but am unsure on the specifics.
So the research field will provide a Homunculus companion or a feat of the same name. The Homunculus will have stats similar to a basic animal companion and have the minion trait.
All the advancement feats for companions will be added to the alchemist feats with a prerequisite of having a Homunculus Companion.
A few new feats along the lines that rangers get to give the Homunculus extra synergy with the alchemist should also exist like giving the Homunculus proficiency with alchemical bombs and weapons equal to their creator.
Their field discovery should allow them to perform the animate object ritual without a secondary caster and using a Crafting check instead of an arcana check.
I need to look at the stats of AC's a bit more to figure out the specifics but what does anyone else think of this or have any input?