Hi @MicroBahner -- Thanks! Let me clarify my question: Suppose I've transferred my sketch to the arduino, setting the VID/PID to "Combination 1" at that level, but the bootloader has VID/PID "Combination 0" at that level.
Now, then, suppose I connect this programmed arduino to another computer or host device. Does this new host device see the arduino as Combination 1 or as Combination 0 or is there a complex interaction between them (it sees both Combinations, at different times/situations)?