Im wanting to play a piano intro from a recorded track.
Could I load the wav then set the song to trigger it with midi?
This is very tricky, and it is likely possible through the use of the custom drumset if you reduce the its overall size of it to have enough space for your piano part, and then making a tricky intro part consisting of a single note that will trigger your wav file.
I wouldn’t recommend doing so with the current firmware version, but it is (in theory) possible.