The issue may be that I can't get to the proximity wire in the handle end where the resistors are, to make it a true straight-through and bypass those resistors. That COULD be the solution. Does anyone know a way to disassemble the NACS handle from the end of the cable without breaking it?
I bought
this J1772-to-NACS adapter to build a custom L2 adapter (long story). Disassembly was easy by first removing the flange portion from the J1772 side using an oscillating multitool, then once mostly flush with the J1772 inner insulator stand off (that houses the recessed J1772 side pins), I used a basic 4-1/2" disc grinder to take it down fully flush around the whole adapter. Once done, the two halves are held together only by the short layer of "glue" between the two halves, so a quick pry with a flathead screwdriver separates them lickety-split. Inside, the heavy NACS connectors appear as one solid straight through piece to the J1772 pins. It looks like it's offset CNCed (with perhaps stamping the final pin shape) and plated with electroless nickel.
I used bare 24awg solid wire to wirewrap my stripped 12awg stranded wire to the pins, then used my grandfather's circa-1940s 100W soldering iron to flow the connection with a bit of 60/40 just to give it a positive physical connection that couldn't vibrate loose. I wish I had cut the long J1772 pins shorter to make for a smaller/lighter adapter, but I was too lazy to redo it after soldering, so I don't know what the material is made of. It might be copper, but my guess is beryllium copper, which is why was hesitant to cut them, as I didn't have a mask in immediate reach and beryllium is highly toxic to us breathing meatbags.
Even if not an esoteric copper alloy, if it's beryllium copper, they would likely handle the amperage without issue for the relatively short SC session. For the SC adapter, leaving the pins uncut and tightly wirewrapping the J1772 side with high-strand cable I think would work quite well. You might be able to find some ferrule tubes to compression crimp the wire around the pins as well. Grabbing one of the adapters for 10 bux and giving it a shot isn't much of an investment if it doesn't work.
All that said, based on the schematic, you can likely just "open" R1 and R2 resistors in the NACS handle by strategically putting them into overcurrent condition by connecting the PP and GND lines to a high-current/high voltage power source while ensuring that S1 is in the "open" position. It would be best to do this from both the NACS connector side and the pedestal side of the cable, to lessen the chance of the PP line going open. If successful, the R1/R2 path would go open once one of them overheats enough. This would of course also cause S1 to be non-functional, but I think that's the point, right ? If you can determine the values for R1/R2, you can try to mock up the circuit yourself to see how easy it is to burn up the resistors vs the cable.
I'm excited to hear how you make out on your next steps !