I have one of these J3400 to J1772 adapters so I can connect my Hyundai to a Tesla destination charger. They’ll probably get more popular as J3400 becomes the primary standard:

I’m curious what would actually happen if someone were to use such an adapter with a J3400 DC fast charger. I know it can’t possibly work because the DC charging pins are connected to the vehicle’s AC pins, but is there something in the J3400 standard to notice and reject such an adapter before DC voltage is applied?

I’m not sure if J1772 vs. CCS1 adapters contain anything that the signalling protocol could use to identify which is which. If the DC charger were required to passively measure the battery voltage before sending any power, that would probably avoid the “magic smoke” problem, but does the standard guarantee that this will happen?