Issues with Mini5+ extremes of step rate compared with duet 2 mini 5+

[T3P3]

https://forum.duet3d.com/topic/31751/discrepancy-between-speed-limit-between-duet-2-and-duet-3-mini/4

[T3P3]

relates to 3.4/3.3 firmware - retest with 3.6 firmware and if still an issues then open a new thread on the forum.