On the extended tab, I think the BLM cell labels in the middle are reversed.
you mean reversed left and right? or 0-18? it's certainly possible. i'm an open loop kinda guy, so i never really tested it beyond it reading a bunch of 128s, so if you could confirm that, i'd really appreciate it.

Just did two successful flashes to two different PCMs using eehack 4.0 Beta1 on a Dell Laptop running Windows 10 through an Arduino board and a standalone harness that looks very similar to yours. I did not try any of the accelerated stuff; I'm in the middle of nowhere right now.
awesome! that acceleration stuff is pretty safe, in beta 2 it's enabled by default.