I don't fire my PMC pieces, but rather leave them to dry on a warming tray - it works very well (I do have a kiln, but I prefer the warming tray method for PMC)
Please explain further – does the heating plate raise the temp high
enough to burn off the binders and reveal the metal? How long does it
need to be there? Where did you get the heating plate? Is it safe to
assume it costs less than a kiln?