In news more interesting than the pointing out of tiny audio errors (lol), I've completed work on the new 5.1 for ESB. Just waiting to hear back about doing the upmix.
There ended up being four changes to the main channel sound of the '93 mix; two of which were repairing glitches, the other two being creative choices. The first is the insertion of the snowspeeder crash sound from the '80 stereo, and the other uses the more complete and unedited music cue for Boba Fett's departure as heard in the '97 mix.
I was considering including all of the relevant SE music edits, but in the end this was the only one that made a positive difference. The original edit of this cue is cringe-worthy, very clumsily done and distracting, and I think the scene is improved by using the music as composed. But the Imperial march transitions seemed too loud for nothing happening onscreen, and the others aren't really significant enough to bother with. That's my opinion, anyway, plus I'm accustomed to the way they sound, and the fewer changes overall the better, generally speaking.
The LFE channel has been optimised to blend with the 1993 mix, similarly to what was done for Star Wars. Being the SE, there were several bass effects way louder than they should have been, but many were at a strong level that fell short of being overwhelming, so I didn't have to do that much. A couple times I added bass where there wasn't any or brought up the existing volume to be more noticeable. All the SE's sometimes have this weird thing where bass doesn't come in until about 1/4 second after the main channel sound effect it accompanies, but in some instances I find that a more direct synch gives better results.
I should point out again that this is not an exact 70mm mix for Empire--without an actual recording to base it on, no version could reliably be named as such. However, the overall feel of it should for the most part be very similar, with strong dynamic range and powerful bass, and a general sense of 'rightness'. Hopefully it will be available soon.