I would say that the nature of the tetrax and deerhorn is quite different from that of the Rollz, and as such the rollz might simply augment your relationship to those instruments, and probably take you in some new directions. You could also consider building some sort of mixer/attenuator combo for the Rolls which would give you a little more control/nuance.
Personally I’ve been thinking of building a Rollz, or at least a few of the component circuits, to add some hands-free rhythmic modulation sources for my Serge/Sidrax combo. I haven’t really seen enough of the features of the Rollz demonstrated to justify the investment, but I might just take the plunge and see where it takes me.