Hmm, I had an idea, maybe someone could check this out for me...
What if, instead of editing the lgps, we simply made a subfolder labled "battle" (lets say for example) and pu that in the data folder. Would ff7 look in there for information, too? I know that thats how some mods for some games work.
I think this has a chance, becasue the LGPs probably have to stay consistant in size, and not all the files in it. But if ff7 sees two items labled "battle", maybe it'll go "hmm, whats in the folder?" and take information from there, too.
just a thought.