It should be noted that there are several different fullscreen transfers of this film that often have the pick-up on different sides of the screen. For example, when Kirk first beams over to the floating office at the beginning, one full screen transfer shows Scotty, another shows the transporter operator next to him. There are a couple of moments when this sort of thing happens, but that's the one that springs to mind.

If a project were to attempt to combine sources in this manner, the Special Longer Version scenes ought to be checked to see if there isn't more information that could be incorporated because of this.

I don't think there were any audio remixes after the Special Longer Version was cut, though. The VHS and LD audio tracks were identical as I recall — it's a very center-heavy mix.

Additional variations: while the subtitles in the Klingon section were always in the same font, there are some video releases where the spoken Vulcan has the subtitles in a different font.