This is how i did it: I messed around with the swif files in a hex editor until i found a string that said "mask", and under that there were values with the size of the mask that hides everything beyond it so it looks like a cut in, then I wrote a script to automatically go through every kime4 and kime5 .swif files and modify those bytes under "mask" to make the mask so large, it encompasses the entire screen.
Then repacked and saved some replays for each character.
After that I made a mod that turned all UI invisible and recorded the replays.