@phaedrux Thanks, I will try that later on after coffee!
I can see what is read as e2_stop on the Duet schematic is SG_TST on the pinout of the ribbon connector on the duex5 schematic. Interestingly although this is labelled this appears to be left floating with the label not appearing elsewhere on the duex5 schematic. The only thing that comes close is each motor driver chip has a pin labelled SG_TST but according to the schematic this is purposely unconnected. Something seems amiss here, why label an input/output on a schematic and then leave it floating? Better to explicitly label it as not connected and leave the label off?
Edit: changing to deux.... worked. Just had another issue that the A axis is no longer homing as expected. Maybe todo with changing to fff mode from CNC. Will hold off marking this complete for a while.