My engine uses the kill switch to reset fault/status codes - Will I still be able to do this with the MOB+?

Yes, some engine brands motors use the kill switch to toggle ON/OFF with the mechanical switch to reset the codes (after service etc.).

This is done in the same way with MOB+, by clicking on the xFOB ON/OFF in the same toggling pattern. Normally toggling ON/OFF on the xFOB 3 times within 10 seconds.