I can unpack the FLATOUT.BFS file just fine using the command bfstool extract FLATOUT.BFS Output, which gives me an Output folder, which contains a data folder, which has 12 sub folders in it. However, if I were to repack it using the command bfstool archive --format v2 --file-version 05050420 --filter foho --copy-filter foho FLATOUT.BFS data, I get a .BFS file that is around 500KB bigger in size even though nothing was changed. Using this .BFS file causes the PPSSPP emulator to crash. What is more odd though, is that both .BFS files give identical data folders when unpacked. All I'm trying to do is make the three playlist .bed files identical so all music plays everywhere, and to add some new songs. When I initially tried to modify those files, the repacked .BFS file would just freeze, either at the copyright info screen or on the start screen which was missing the background.

As for which one I'm using, I'm using Sewer56's fork. Tried this one, but it says the only valid value for format is bzf2001