You probably understand what it’s like to work up there, crouched/kneeling/whatever on a plank that is sitting on a couple of ceiling joists or rafters or whatever one may call them, and all the other discomforts of working in an unfinished attic . . . the older I get the harder it gets and the easier and quicker I start cramping up when contorting my body to work in the places I need to work up there.
@immatthewj I totally empathize. If it can make you feel any better, mine will entail spending a day in a spider-infested crawlspace with 18" clearance under the beams.
Honestly, before you go to too much trouble you might want to assess the worst load you’re ever likely to plug into your existing 12awg circuits, before you declare them inadequate. In my most humble opinion, unless you’re planning to biamp Apogee Scintillas with a quatuor of Krell KMA-800s you’re probably fine 🙂