Instrument keyzones

The keyzones in Renoise are for internal samples only. VST plugins have their own velocity responses.

There is a workaround that you can use to also devide responsiveness on velocity and keyzone layers, but this requires using an external vsthost, virtual midi cable software and a plugin called polysher.
I have explained in this topic how you can do basic vst control on keyzone splitting, you can also set the velocity ranges to send:

I hope in the near future that Renoise allows internal midi routing so that these ackward solutions are no longer required, but this is currently the way to do it.