Yo Paul, this is really cool man, especially on a compositional level. Yours is probably the best use of secret of mana sounds I've heard outside the original soundtrack. I think your work here would be greatly and enhanced by a more accurate use of the sounds on a technical level themselves. Unfortunately the only secret of mana "soundfont" available, currently, and what you were using, was made back in the early days of snes sampling by blitz lunar, when openspc was the only option. Changing from 32khz to 41.1khz back then when exporting the samples from modules often would cause the looped portion of the samples to be out of tune with the attacks, as is especially the case with the first ripped secret of mana set and is pretty audible in your song, this is totally not your fault and would be easily fixable by just replacing with the correct samples.
Also, squaresoft games in particular, had a very specific kind of filtered delay that again is very simple to replicate with the right settings, if you'd like I'd love to help convert your song to sound even more accurate, not just for like nitpicky anal reasons but I think it will sound even better that way as the writing itself, the compositional work you did on the track is really really neat and I just want it to shine even more.
You mentioned doing evemore, not sure if you found this in your searches but, a couple years ago, I did a song with half sounds from secret of evermore, half from secret of mana, and it switches back and forth then combines. I actually used lunar's improperly ripped mana sounds for it at the time, I just avoided using samples with detuned loops as there was not yet a good way to fix it like there is now, though the DSP is a pretty accurate emulation of the original (only used during the secret of mana portions) and that helps give the sounds that special squaresoft ethereal ambiance. You can here that one here (secret of mana sounds start at 0:45): https://soundcloud.com/shnabubula/evermore-densetsu-secret-of-mana-and-evermore-instruments