A / B Switching

I don't think so.. Macs are tough.. You need a second amp. If you want to really A/B it right.. The OLD Mac way.. Was A or B or A and B. I like both ways.. It just takes a second amp.. A/B amps switches, are not a great idea.. like you said.. Different impedance matching problems with just a switch.. If the speakers are the same, impedance, that problem is solved, with an A/B switch, BUT the CRAP switch and cables.. LOL Your still stuck with that..

You're better off with the preamp A/B and a second stereo amp.. SQ wise.

Regards

I used to use a Niles Audio SVC2, high quality, controls volume also

https://www.ebay.com/p/1475699276

Thanks guys for the advice. My listening room isn’t huge.  I may have to end up running the DQ-10’s off a separate system in another, larger, room just based on the space requirements

You will more likely burn up the switch. They are all rated fairly low.

way overkill - but this thing works and it is quite a truth teller!

https://avahifi.com/products/abx-switch-comparator

iirc niles made a line of regular speaker selectors... ok, not great fidelity but did the job safely