Possibly similar issue on my modded HEVO: https://forum.duet3d.com/topic/8213/ringing-at-20-70mm-s-mostly-during-acceleration-deceleration
I didn't update the original post, but what I've found is this:
Since two motors work in tandem, they probably tend to vibrate (reach resonance) more often than other printer geometries.
The resonance might appear like ghosting due to high jerk, but it's suspiciously consistent, usually at around one full step in amplitude (e.g. 0.2mm - amplitude
not distance peak to peak - for HEVO 1.8 deg ).
Loose or bad components on the axes may increase the vibration.
0.9 steppers help but not eliminate it.
Normal to slow speeds are worst, 60mm/s being worst and above 90mm/s being better and 120mm/s or more being best.
It would be interesting to see if any of this applies to your HEVO...
