Seems like you didn't get a reply here either, Espyo... I was surprised that the current TAS didn't take that route, I just assumed that it was slower for whatever reason.
Anyway. I recently started TASing this game as a promise for TheMexicanRunner. So far I've only completed the first level:
http://tasvideos.org/userfiles/info/16775695368019943
There are a couple of differences between the SNES and Genesis versions. When I started it, I wanted to use SNES just because of better sound/music, but I'm noticing a few things that differ.
1. Takes longer to reach the Title Screen in Genesis.
2. The options menu is faster in Genesis.
3. I believe Simba's hitbox is different. There's a specific jump in the first level where Simba will hit the ceiling easier than in Genesis, wastes some time in the TAS.
4. The Hyena attacks at once in Genesis instead of waiting.
5. Simba falls longer at the start of Graveyard in Genesis.
Most certainly a lot more, just what I have spotted while fooling around.