Apologies if this kind of thing has already been mentioned elsewhere, but I think the thing I would find most useful to add to Renoise, aside from the oft’ mentioned pattern-live-arranger thing would be a few new integrated devices which enable more feedback of control, so for example (which i mention in the thread below) if there were a device which allowed you to automate change of instrument or sample within a track, using the same pattern, i think this could open up so much potential, for live function aswell (even with no change in current pattern interface), and although i appreciate my idea may sound abit confusing, if this was done in an optional device which you just insert as you would an LFO, then there is no compulsion to use it if you dont want it or wreck what is already integrally great about the tracker. In the thread below i kind of explain what I would want to be able to do ideally, which I will have to programme in max/msp, but if it could be done in renoise it would be cool. Also, I want to be able to assign an LFO to the GUI colours. And when is V-Noise (Renoise-Video) coming out? Maybe a renoise modular device 
https://forum.renoise.com/t/switching-samples-with-one-automated-control/21450