Right now there is no easy way to map a set of samples to a single note and distribute them in the "velocity dimension". You can layer them, create drum sets, distribute them throughout the keyboard but there is no option to them distribute velocity wise.
Ideally, I'd like to be able to select a set of samples (in the sample browser) and drag or somehow assign the selection to single note. The order of selection should define the assigned range of the velocity for each sample. I know drag and drop is already possible and the y direction defines the note spread while dragging. How about using the note name area as "drop selection as velocity layers"?
This feature is missing in Renoise and Redux but for me Redux would be more important.