I'd like to know for sure if Empire was remixed in 1985 or not. If it wasn't, it stands to reason that Jedi wasn't, either.

However, I have to say, I've been listening to DJ's capture on mixing-quality Sennheiser headphones, and I haven't noticed any tape hiss as you mentioned.

I have noticed what may be distortion due to capturing in the scene where Luke's X-Wing is flying through Dagobah's atmosphere, but that may have also been intentional (almost like the X-Wing's instruments are getting static from the atmosphere or something).

If the post-1985 LD was in fact remixed, I'd sync it anyway - it'd be nice to have the 1980, 1985, and 1993 mixes all synced for posterity.