As a person who really loved the movie and a lot of the themes that it tries to convey, I do think the film could be tighter and more cohesive to make it a smoother Star Wars experience.

Trim (not cut) the Hux and Poe phone call. If it’s shorter I think it could be effective humor.

Add deleted scene that happens right after “Where’s Rey?”. According to RJ that scene is basically Poe bringing Finn (and the audience) up to speed on what happened in 7 and the fact that Rey went to Luke’s island to fetch the last Jedi. Then BB8 shows Finn a hologram of Rey’s “we’ll see each other again” moment, which basically ignites Finn motivations. Why this crucial establishing moment was cut? I do not know.

Cut from Rey’s “I’m not leaving without you” to her following Luke up the mountain and sensing the Jedi temple. As much as I like the Luke’s daily routine sequence, it can be a real pace killer and it just demystifies Luke a little too much. His character is a question mark at this point and that sequence just answers questions we never asked.
Maybe trim some of Leia’s space walking. I know it’s kinda corny but I personally don’t mind it too much. She’s in Zero G so the amount of force she requires to pull her weightless body can’t be too much anyways.

Add more SW wipes during the intercutting between planets.
Restructuring of Canto Bight:

As Finn and Rose jump into hyperspace follow their storyline all the way until to when they arrive at the Casino.
MOVE UP BB8 getting slotted with coins to after “This place is awesome” Then cut to Rose describing the codebreaker they have to find and we wipe to Rey talking with Chewie in the falcon which precedes the second skype call with Kylo.
Wipe from Kylo’s hand to champagne popping in the Casino and the whole scene plays like it does.

Add third lesson. This scene should explain why Rey was so willing to fraternize with Kylo. She gets disappointed by Luke and looks for answers elsewhere. ie the cave and Ben.
Add wipe at the end of Yoda’s scene.
Maybe add deleted scene of fight between BB8 and BB9E, if anything just to make his action hero moment when he saves them with that AtSt have better context.

Remove chrome dome line. That was just a lame one liner.
Remove Rey’s “I like this!” when she’s shooting in the falcon. I think the cheer that preceded that line told us as much.
Remove the shot of the family portrait in the falcon as to not mislead the audience into thinking that the film is over. That way when the broom scene comes up it feels less like padding.

I think when we see the deleted scenes we’ll be able to tell what’s feasible and what’s not. I pray to God that they don’t have timecodes like the TFA ones.

Anyway, that’s just me.