Thanks for the suggestion, TVG. I don't think I'll choose that one but at least it got me off my butt. It's actually not too bad to look at a game soundtrack here on OCR and see which tracks already have remixes after all. For reference, the tracks in Secret of Mana that would be eligible for PRC right now are:
a conclusion
calm before the storm
ceremony
file select
did you see the ocean
eternal recurrence
i closed my eyes
in the dead of night
it happened late one evening
meridian dance
monarch on the shore
morning is here
mystic invasion
now flightless wings
prophecy
secret of the arid sands
steel and snare
the curse
the little sprite
the oracle
the wind never ceases
Maybe I'll choose one of them