When you ask about mods, what are looking for it to do that it doesn't already?
Mine's a vintage MIJ and it's killer. You just need to dial in the right settings. You can get some great warm tones from it.
Instead of starting a new thread about this, I bought a BF2 a while back(MIT) and i thought that it was broke...let me explain, when turned on there is this loud background flanging static feedback sound when the pedal is engaged. Its very annoying. Just recently I reading some threads about the internal trim pots and wondered if tweaking the one labeled RES would fix this problem. I read that the other two were not good to tweak, but knowing the jacka** that I bought this from he probably experimented...so if you have any suggestions, please let me know!