For a while I was looking for a slowdown fix for FFT: WotL and I found a patch made by someone (I don't remember his name, sorry). But It was very difticult to apply his patch because his patch was an ips to apply on the iso file. So if you don't have the same iso the patch won't apply properly.
So I've decided to make a patch wich is compatible with all version of the game, evan Jap version and all modified iso. So even the modified game can be patched with it.
You must have .net framework 4.5 installed to open the patcher.
All credit goes to Archaemic !! He found the way to fix the slowdown. I just made a windows program to patch your iso.