It's likely that Dark Secret wasn't undubbed until now due to the localised versions' game data being packed into the .farc archives... or due to a lack of interest, as the game is not too good no matter how you slice it.
xdelta patch: https://archive.org/download/tenchu_ds_undub_patch/Tenchu -...
The previous public efforts of undubbing Final Fantasy Crystal Chronicles: Echoes of Time have started and ended more than 10 years ago, so here's a complete undub.
xdelta patch: https://archive.org/download/ffcc_echoes_of_time_ds_undub_patch/Final Fantasy Crystal Chronicles - Echoes of Time...
S O L V E D
Hello. I converted all of the audio I needed to edit from BCSTM to WAV with the vgmstream, split and merged WAVs how I wanted, while preserving the audio specs, then converted them back and put into the game.
The in-game issue: when it's time to play back a modded audio file it does...
Caller -"Everytime I start a Pc game on my S24, playing on a external monitor, someone calls or texts me, n it kicks me out of the game." Customer Support - Click (hangs up)
I found it funny cause many many years ago, had a roommate in college that did this same dumbass branding of the school logo, but it didn't look anything like it after it healed. Just looked like a birthmark.