Hmmm… Just looked in this document here (http://www.zendrum.com/Docs/Zendrum_Z4_Manual-ZAP.pdf) and it is clearly stated in it, p.26, in the remarks concerning ‘Velocity note on/note off’ :
on @ 10ms
So, I tried with my Akai MPD32 controller and the shortest notes I can get are 17 ms long (guess I’m not as quick as should be…), which correspond to 23 ticks in Cubase at a project tempo of 168 (see the screenshot), therefore perfectly manageable by it. I also tried the ‘Lenght compression’ Modifier at a value of 3/1, combined with the ‘MIDI/Freeze MIDI modifiers’ command on such notes and I indeed get notes at around 50-65 ms of length.
This should be enough for any usage, as the MIDI modifier is applied just on the dedicated MIDI track used for your Zendrum controller. It should prevent you from bothering about any finite value for the ‘Length comp.’ modifier.
So, I suggest you to give it a try again… Recording few strokes from the Zendrum, what are the actual note lenghts of them obtained in the list editor ?