So got around to PTing the head deck and the cylinder sleeve/engine deck.
TLDR didn't find any relevant indications
What should have probably been an hour job turned into a few, as I wound up PTing the engine side 3 times and the head twice. Why so many times? Well the engine block I still had the piston at TDC trying to save some time on the reassembly and that penetrant just sits between the top ring and the top of the deck. Put that developer down and it just pulls too much penetrant back out. Don't think it would have kept me from finding any significant defects as I was watching the entire time, but I was already here and my hands dirty (kidding i wear gloves) so decided to do it until I was happy with the test. Put the piston down in the hole a bit and test again. Those machined edges really hold that penetrant too and quickly saturate the developer as well, which bothered me with the second test, so 3rd times the charm.
Anyways, didn't find anything relevant and I think I tested it enough times to be sure of myself. I want to say this is a good thing because it means my parts aren't cracked, but it's also bad because that pretty much means i still have no clue as to why my bike was pushing coolant. Still haven't pulled the head gasket apart which I plan on doing and i still haven't checked the cylinder sleeve/engine deck for flatness so there's still those possibilities but i'm not thinking i'll find anything. Obviously will report back if I do.
105mm is the bore which works out to 4.13" or so. Pretty dang big for 4 head bolts imo. Not sure if that's the actual issue but if my head gasket investigation doesn't turn anything up I have no other idea what it could be.
Two developed pictures of head are initial application of developer and 10 mins after
Cylinder/engine block is initial application, forgot to take picture 10 mins after