@phaedrux I am finally printing! I used the SeeMeCNC config files (which were almost identical to my own) and took apart the hotend again reassembling it very carefully.
I've got good power supply, good extrusion, and no heater faults.
The Wifi is still failing to initialize about 10% of the time, annoying, but manageable with a quick USB plugin and resetting the system.
Things are going so well, I'm tempted to start rolling some of this software forward...