@Alva RRF actually interprets those error bits already. On the pre warning for overtemp you get a warning on the console, and the fake driver thermistor will report 100C s you could setup a thermostatically controlled fan using that value.
In addition, driver errors generate events, which you can handle in your own macros. See https://docs.duet3d.com/en/User_manual/RepRapFirmware/Events#events