The USB-C standard and particularly the USB PD (power delivery) is so complex it almost feels comical.

The PD standard document (freely available on usb.org) is over 800 pages long and features a lengthy part about the role of the cable alone which is mostly hidden from the user. Here's a short video about this issue: https://www.youtube.com/watch?v=6bZ0y9G-4Pc

Thanks, that's pretty much exactly what I found: https://en.wikipedia.org/wiki/USB_hardware#Allowable_current_draw

Interesting approach, never thought about using the cable for something completely unrelated.

Yeah, it's not really getting easier...

It indeed is, but there seem to be no testers available for resistance measurements.

That's true, they explain this in a different video: https://www.youtube.com/watch?v=y9vXDy_zt4I

Haha pretty much