Yeah, looking at those can probably tell me something, i want to implement something similar to that in a mod I'm somewhat working on as i managed to make the game change what model comes up in the house you can buy, but i wanted to take it further and make the battle model change as it could make it 'better' as for things like the flashback, we could try to include a 15 year old tifa in the party as well.
but changing the actual models would be tiresome as we'd have to say 'okay, now that the outfit is changed, save the game, then open up the battle.lgp with lgp tools and insert the files from (folder)...' XD