Rear Brake Drag after Caliper Replacement

Hello friends,
I recently replaced both rear calipers + caliper mounts after the parking brake froze up on one side. It turns out the parking brake cable is also frozen on that side, so it remains disconnected. I also replaced rotors, pads, and the outer hoses. I made sure to align the piston with the pin on the pads. I bled the brakes in invalid mode. The slide pins seem to move freely. The brake pads also seem to move sufficiently freely (not super smooth but smooth enough)

I now am encountering persistent brake drag on both sides. The heels only turn ~1/2 a revolution when pushed. When I first put the pads in before pressing brake at all the wheel spins freely. Once the brakes have been depressed at all, the brakes drag. This is leading to reduced MPG and very hot rear rotors.

I'm really not sure what to troubleshoot next. Most threads point to improperly aligned calipers as the cause here.

Any help is appreciated!