@Phaedrux I didn't have the option to set up the motor in isolation (would have required pretty significant disassembly) but I created some gcode to move the axis up and down and ran it for about 4 hours. This doesn't seem to have triggered the issue. Not quite sure what else to try since the only situation that would somewhat consistenly cause this issue also comes with significant risk of damage as well as losing prints part-way...

@dc42 My M906 is

M906 X1000 Y1000 Z800 I30