What you call "piggy back" is dangerous to your amps. Never connect two amps to the same terminals as they will shunt each other, possibly even with one of them not powered up.
Is the VC on the ARC stepped? If so, simply choose a comfortable setting and always use that for level setting and listening through the AVR. That will suffice as a HT bypass.
Kal
Is the VC on the ARC stepped? If so, simply choose a comfortable setting and always use that for level setting and listening through the AVR. That will suffice as a HT bypass.
Kal