I was curious, say you had the wrong instrument on a track for an arrangement and you wanted to just put it back to a regular SF2 Player without deleting the track, how would you do that?
Just drag SF2 Player from the Instrument Plugins list and drop it over the "wrong instrument" in Song Editor. Same way you always exchange one instrument for a different one.
infact absolutely anything can the swapped in
You can even substitute an existing preset from a VST or a AFP, just bring the unwanted forward, right-click on the wanted preset and choose send-to-active