Update:
I pulled out the parts I'd soaked overnight in Purple Power, brushed and rinsed them off this morning. They came out pretty well, but they could use a little more cleaning in the nooks and crannies to meet my high standards. One thing I noticed, that I wasn't expecting, was that Purple Power is not kind to aluminum if you soak them parts for 12 hours or more. Nothing got damaged to the point where it will be a problem, but I wont soak aluminum parts for multiple hours in PP any more, as it causes corrosion on the aluminum surface. My 3 gals of used PP now looks light toxic waste with a layer of sludge floating on top of it. Now I need to figure out what to do to dispose of it responsibly.
Other than the engine girdle and heads there's nothing else that needs cleaning anytime soon. My valve spring compressor is coming in today's mail, so I can remove the followers and cams from the heads, then after cleaning I can the heads off to a machine shop for evaluation and milling.
Weather permitting I'm going to try to remove the remains of the rear cassette today, that will complete the majority of the engine disassembly, other than the oil pump and rear main seal, both of which wait.
Question: Are the rod and crank journal bolts TTY? If not I'd like to pull the caps and journals to check the bearings. The cylinder still show their cross hatching and there's no ridge, so I have no reason to pull the pistons.