One dead battery, replacement part from alibaba via GPD rep given link. Easy to disassemble via screwdriver and spudger. Works great now. Injection molded piece that held the threads where the hinge attached also failed. Drilled a little pinhole and added a small machine screw, nut and threadlocker. No more problems. Nut goes under the plastic hinge cover. The fix is literally better than original.
Other than that, the only issue I've had is getting grub to see the screen as landscape. Grub config options seem to get ignored. Oh well. Standard rotation is sorted with boot scripts and the OEM Windows 10 side works great.