A few more ideas I’ve been mulling over:

Vader’s voice: Something that has always bothered me since I first saw the film as a child was how Vader’s voice effect is quite noticeably different from the other two, not that the Original Trilogy was consistent in this regard to begin with (cough ANH “man in a suit” cough), but Jedi seems to have an overmixed flanger or phaser effect to it. If there’s anyway it could be made to sound more like ESB that would be wonderful.
In regards to Operation: Decutify Ewoks, I have found when watching similar “cute but evil” creatures in other media that a lot of the scare factor or creepiness comes from a good mix of making the creature seem all cute and cuddly, but then subverting it with some subtle elements (and some overt ones as well) as to their true nature to achieve the desired effect. As a result, my personal recommendation is to treat the Ewoks in precisely that manner.
I do think the space battle could be extended by about a minute or two, namely the sequence right before the shield goes down since it seems a bit rushed IMHO (please let us see an actual ship to ship battle between the medical frigate and that Star Destroyer rather than them just sitting there).
A couple additions that could be made have already been suggested, but to reiterate them: A. near the start of the battle when the rebel fleet arrives a ship hitting the shield that alerts the rebels to it still being active (Lando’s dialogue would need to be reedited since the film in its current state suggests that this doesn’t occur), and B. add some Interdictors from Star Wars Rebels (which according to the new canon DID actually participate in the battle) which could add a whole new dynamic to the battle since the rebels can’t simply escape into hyperspace while those are active, as well as the Victory-class Star Destroyers mentioned earlier.
It would be awesome if “Commence primary ignition” and the bass drop could be added when the Death Star II fires after “Fire at will commander”, although I am aware that it is technically an “improved design” and those things might no longer apply.
Agreed with the poster above who suggested that R2-D2’s bleeps and boops need some effects from 4 & 5 mixed in.

And that’s all for now.