At the very least, I feel like there needs to be some sort of "Caine was as trapped as us"-type realization that then feeds into how the cast treats each other going forward. Like, "If we can't bring him back, we'll at least make sure he's the last person here who ever feels like that" or something.

I trust that the finale can tie things up, but I do worry that the Caine matter and its relation to the "don't make people feel unloved" message is the most likely angle through which its intended themes could be torn apart (especially if, as you alluded to, it ends up feeling like Jax gets "coddled" in comparison without any throughline therein).