Hal, your 4.2s are my archival versions, and I love everything you’ve suggested for 4.3.

The only thing I’m just not sure about is the Emperor, Vader and Tarkin looking out on a prototype Death Star, especially one with the dish on the equator.

Firstly, a prototype Death Star has exactly the same issue as the real one - that it’s just part of the slideshow where pieces are put into place to line up with the OT.

Secondly, there’s nothing in the films that suggests a prototype was ever created, so I think it adds something new to the world without adding anything new to the plot, or any meaningfulness to our characters.

Thirdly, I think the reveal of the Death Star is really beautifully done in Rogue One (and well set up in Rebels, for those that watch that), and that seeing it early takes away from that.

For these reasons I think either of your initial ideas work (leave it, or replace with Coruscant) - personally favouring Coruscant.

EDIT:
One question though - while you are revisiting your edits, could you please consider releasing identical versions but retaining the original titles of the films in the crawls? I respect your right to put your mark on them, and to recognise them as significantly changed movies - plus I’m not a huge fan of the original titles - but personally I’d like to pretend that yours are the master versions as originally released. (I hope you take that as the compliment it’s intended as.)