Made a nice little USA version of the game so far. Changed the game's preview icon, install data icon, new data icon to the English logo, the preview music as mentioned in the above post, and I renamed all the kids to their dub names (Yamato=Matt, Jou=Joe, Taichi=Tai, etc.), a few Digimon (Piyomon=Biyoman, Tailmon=Gatoman... and seriously the dub name for Gatomon is so much better. Tailmon? Like really? Get outta here... lol) across the text boxes and episode recap summaries. I started to edit the story, but quickly lost interest over how daunting and impractical it is to do so with a hex editor. If I could manage to do the editing through Falo's tool I will as it seems much easier to keep tabs where line breaks would happen and stuff, but for some reason the tool can only unpack the story .bins not open and edit them.
In case anyone in the future wanted to know since it was never fully explained on here and I spent hours scouring every comment and trying to figure it out on my own, I believe all the story bin files go from ID03520 - ID03622. Then there are like 6 useless ID files to the naked eye when opened with a hex editor before the .bins containing the pmf's (videos and such) begin.
Music was easy enough to mod too, but does anyone have a clue why the audio in the 3840 file wasn't changing? I dubbed a few Agumon attacks as a test. Converted the wavs to at3, compressed at 32 bitrate, said it reimported the 4 files back into the afs2 file no issues. I even unpacked right after to confirm they were in there, albeit showing up as dat files, but went in and in game the lines were still in Japanese...