Fair, a wire break can be annoying though, often they’re intermittent, and the display often doesn’t respond fast enough to show that, but thermal protection will.

I’d totally consider taking a look at the connectors to the board for the heater cartridge, see if there’s good contact being made, check for any signs of things like scorching check end-end continuity. Looking at the schematics for that mainboard Btt skr 1.4 it looks like there are LEDs on all of the MOSFETs, it will give you a visual indicator of the board state, to help narrow down your troubleshooting.