Sparky, RogueLeader, I really like the idea you’re throwing around here. TROS really does little other than try to justify itself, whereas TLJ does feel far more conclusive. I agree that the only real ‘meat’ of TROS which also concludes a key part of the story is Rey vs Kylo around the old Death Star wreckage, and Kylo’s Han dream.

I think you have either two options - a ~15 min epilogue ‘movie’ with a crawl which would explain stuff, or appending it to TLJ, which I think is better. I don’t think a duology is problematic even if a trilogy was the norm. I know it’s a little clumsy, but you could insert a ‘four months later’ title card if you had to.

As much as I like it, if you were going to excise anything for time you could probably cut out the entirety of Finn’s storyline. That’d keep TLJ a lot more focused on the pursuit, Snoke, and Rey’s training by Luke.

The only thing I’d add in to a TLJ+TROS ‘final’ movie would be to cut in the flashback of Luke training Leia over the scene where she’s floating in space just before the Poppins flight, and then end with Rey training under Leia from the beginning of TROS.