Thank you for asking! I have a follow-up post here detailing what the actual issue was (incorrect temp readings from the printer, hotend only reaching ~half reported temp), but the actual root of the issue remains unknown. The board seems to have been the issue, as swapping in an SKR mini has fixed it (and improved a couple other things, definitely recommend this board!), yet I still have no idea what could’ve been the problem with the other one. It was relatively new, had been working for weeks, tested completely fine on a multimeter, and even read correct temps for the heated bed when the thermistor was plugged into the hotend port.
In short, the gremlin did not move out, but I’ve bulldozed the house and built a new one around it.