Got slightly further before it jammed? I'll take it! It still jammed, and I'm pretty sure I know why: Prusa Slicer starts with the fan off for better adhesion between layers but I was using that same fan on the cold end of the extruder to keep that side from getting melty soo...

Things got a little too melty. Also It looks like the default fan on the E3D nozzle is 24v, so I'll get a 12v one with ideally more CFM to get more cooling power on the cold end. I'll probably do a full teardown and diagnosis while waiting for those parts, in case I can think of a way to get this running before those arrive. The default oozebane settings might be way too high, causing liquid metal to jump into the cold end, among a few other possible issues.

Really feeling this web comic right now...