Hmm, I'm at a loss. I know occasions where the OST is different than the actual game. It'd be interesting to see if these missing instruments are present during game play in an emulator or real PSX.
I could check, it would just take some time to get to a point in the game where it plays that track, since if I recall right, it plays pretty late into the game, and the in-game music player only plays the first 10 tracks from the OST, which are all the sung tracks. I'll post back about it when I get around to that.
Alright, so I finally got to a point in the game where The Wanderer plays (first instance of it playing is in past Orange Village inside Kururu's head, right after you talk to Cherie in the church, the music changes to that song). I captured the audio through a capture device and played it back, then listened to both versions of the PSF, the one with the Davironica driver and the one with the original patched driver. The original driver version does actually sound correct compared to the Davironica version, it does indeed contain the missing notes. Neither the Davironica driver nor the Mark Grass driver play those notes. However, I found that I do not need to handle more than one SEP to have it play correctly. So the 7z I linked earlier works fine.
Question: This just occured to me, but I've heard that the reason there's no PSF rip of Megaman Legends 2 is because it uses a custom driver, thus making the sequences non-compatible to generic drivers. Could VGMTb's "stub tool" be used to create a MML2 PSF rip? Obviously, this is a question, not a request. If the answer is "possibly" (or similar/yes), then I'm going to have to ask for help using the tool, because I've been wanting a MML2 PSF rip for years!
Back on topic - congradulations! I'm glad you were able to find, and fix the problems. That's pretty cool that the tools have been developed enough to make ripping PSFs much easier than it used to be. Mouser X over and out.
The stub creator is typically used for standard PSF sequences. Someone could potentially write a custom stub "psfdrv.c" file, but they'd still need to reverse the custom driver. At that point, there wouldn't be much advantage to using VGMToolbox to do it.