You are probably right about cubase having the worst MIDIclock out there and I don’t think Steinberg is going to do something about it.
I reported an issue about a year ago and started a topic here, but that was not enough to get a response from Steinberg. (an internal Case nr was created, after that…nothing)
In this topic I described my discovery of the “UnavoidableSteinbergMidiClockGroove”
Happy waiting. 