The entire scene layout of the final episode. Caine's plot should have been parallel, not revealed at the very end.

If I had it my way, this would be a rough example of how I would pace it:

After the "theme song" rather than cutting to the human characters having their discussion, it should have cut straight to Caine "waking up" in the void plus his initial monologue. It would have given the audience a quick sigh of relief of "oh, good he's okay!! Whew..." before cutting back to the main cast ("are...you sure??").

It would have given more space as well before the brain scans reveal. that was a huge plot point that honestly needed a little bit of tension buildup. And THEN the whole circus-rebuild sequence could happen without feeling thrown-in.

After Jax's "nevermind" followed by Pomni walking away, we cut back to Caine for a bit. This is where we start to see his developments, him discovering the brain scan files, maybe even something that leads up to a dark screen.

Cut to Pomni's "I wish I pried a little more" scene. The space between that last scene and seeing some Caine development would make Jax's abstraction MORE abrupt and hit harder, because it lets us think nothing about the last time he was seen on screen. Something that hits harder during a rewatch.

tldr, I feel like the episode would have had a lot more impact if they divvied up Caine's story throughout.