Unfortunately I don't know much when it comes to music hacking, so I won't be able to fix that on my own. I believe the current theory is that data stored in HiExROM areas have a slightly different read time, leading to the wonkiness. If that's true, it could be possible to relocate most of the songs to safe areas and move existing data to the HiExROM areas, but that would be like doing brain surgery without any experience.
Right now, I have a note added to the NPC who explains about the Music Player that some songs might sound wonky on modern emulators and hardware. In the readme I'll try to emphasize that it sounds correct in Snes9x v1.51.
/wave, I'm the Lua coder.
The music issues are caused due to the instruments using up too much data (?) so the audio info overflows into the RAM dedicated to the music's echo. There's a "hacks" setting in snes9x(-rr) 1.60 that allows you to separate the echo RAM which lets it play okay.
The MSU patch that was thrown together uses the SRAM for Cyan's Swdtech names (7E1D0A-7E1D0E) because, for the Lua version, I knew
that RAM was unused since the Lua completely disregards the text that's there and prints the skill names directly in 8x8 font (because I'm a scrub who couldn't figure out how to get the wide font to not display the tall glyphs in the 18xx range). So that could be an incompatibility if you just read from that RAM... although the screen to let you change the name is gone anyways so there's not much harm in hardcoding the names.
I think what you have in the screenshots is significantly better than what we have anyways. I've been staring at that GBA font too long, ahaha. We never put together a real EX patch, for EX I only threw together a minimum-possible-effort patch in order to make it playable in English, there's still various gibberish in places. The Lua effort only works on a single emulator, if you don't use that one then 95% of the text in the game is just garbage text because there's no script or monster names or anything else in the base IPS patch.
2.9.4 should be fine to install? I used LocksmithArmy's patch conflict checker
to compare 2.9.4 to what we had done and there was no issues (though for you, of course you might be using some various offsets that we didn't use, especially when it comes to the ASM).
If you wanna talk patches or bugfixes or whatever, we're in #ff6-t-edition on the NGPlus Discord.