Thanks for the info, this provides a great starting point once I get the Duet in (still need to order it).
Right now the printer is still too busy to take it out, but like you, I'm trying to stay close to the original Cetus initially, although I foresee switching to an E3D Titan Aero at a later stage as well, along with 0.9deg steppers, and a heated bed.
Once again, thanks!

HI,

I'm considering doing the same, swapping out the default electronics with a Duet. I intend to use the sensorless homing feature, but I am not sure if that will work for the Z axis. For the Z-axis I still got three difference Z-axis sensors, the original three wire ormerod sensors, the 4 wire one, and the DC42 sensorboard with ultrasonic sensor. Am I right assuming you're using the latter as sensor? Or did you try sensorless home for that one as well?
And how may steps per mm did you configure for the extruder?