@PaulHew thanks
Mechanically and electrically all now works. Something I suspect though is wrong in my config still. My 20mmcalibration cube gets this far:
cube.jpg
Which doesn't look great, before reliably lifting from the bed entirely. I have set Z quite a few times, and checked the bed temperature. This isn't a problem I had with the old stock board, so I suspect the issue is with my config....perhaps something to do with my extruder settings:
https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+4:+Calibration/40#s165
I'll double check them. Will get there though...try again tomorrow!