ToPX, like FVE, would require some extensive ASM hacks to support all the changes/adjustments currently in place on the PS1 version. It's not impossible, but I don't think any of the tools that makes life easier are readily available (hence making the majority of them would be a necessity before things could even start... I guess the "simplest" would be a sort of plug-in for logging/monitoring of data via USB)
Also, looking over those NDX shots, I see the game is as I somewhat feared (full of weirdo designs locks that'd have to be fixed/overcome) - Half-assing just aint an option anymore
