@benhamill Probably.

As my brain cells come online one by one, I think it's not animacy but class of referent?

"Incipient" thus modifies nouns; specifically, nouns of state? So "incipient joy" works because joy is a noun describing a (mental) state. But *"incipient cat" is awkward, because grammatically, cat is a concrete noun; it doesn't describe a state of being.

(Ofc I myself would quibble about that last bit, nyan )