If your track uses the default Cave Story drums or no percussion at all, you could convert the ORG to a Ptcop and then export each track solo (with the muted option checked).
If you do use the newer drums...you could try making a copy of your ORG, delete all tracks except for one, then export as a MIDI. It will still be time consuming, but at least you won’t have to listen to the entirety of your song each time. You won’t have the instrument sounds as they are in ORG but you’ll at least have the notes. Perhaps you could even just export the whole ORG with no tracks deleted as a MIDI and then mess around with it in a DAW like FL.
As you can probably tell, ORG doesn’t really offer any exporting options other than MIDI - that I know of anyway. If you really need the sounds and stuff rendered, it’s best done in PxTone.
