Be aware that texture coordinates are stored in one byte though. If you slap a 4096x4096 texture on there you will only be able to adjust it in steps of 16 pixels. Blender doesn't know about this of course, so it will just look crappy ingame. Anyway I dont think this will be useful for any major modifications, its better suited to fixing annoying corner cases.
The only thing holding back a release right now is that I dont know what to do with normals. Blender doesn't load normals, it likes to compute its own. This looks terrible when imported into FF7, the lighting is way too sensitive and some things that really shouldn't be affected by it are. But since world map lighting is broken in the PC version anyway I dont know if its really worth fixing or if I should just set all normals to point straight up, effectively disabling lighting.