I just tried using 2 PLA layers for support on a PETG project. I just saw the printer when it stopped printing the PETG and loaded the PLA. It printed one dot of PLA on a support tree and then went back to printing the PETG. It is just halfway through a 13-hour print job but I haven’t been watching it and don’t see any more white PLA spots on the camera or direct viewing of the print job.