couldn't we write our own background render routine in a dll, then inject that dll function into ff7.exe where the 'normal' background render takes place? Just overwrite the code in memory to call our function instead of the retail one? Just thinking out loud.
There have been numerous hacks to the FF7 exe (some good some horrible).
One of them was the hirez project (which was a nice idea).
However as I said doing this might be a bit more complicated than just loading a DLL and linking to functions within it.
FF7 is built in layers so several things are going on. The EXE in the PC version doesn't work too well.
The place function redirection will need to go is a bit difficult to decipher because of this. (The original design and the fact the PC version is a bit of a kludge).
Fortunately they left the debugging information IN the FF7 executable this helps.
So basically before you can try enhancing there software you have to know what it did to begin with in terms of graphics.
There is plenty of information in the Q-gears source to give hints of what to look for in the PC executable I suspect.
Cyb