Also, don't underestimate what outboard sequencers can do for your modular build. Case in point: I did a live work a few years ago where I needed several unmatched tempi from a pair of Beatstep Pros. And that was super-easy. Since I was doing this with a digital synth via MIDI (Kawai K5m), I needed the BSPs and a MIDI merger. But the BSP allows you to uncouple its master clock from the different sequencer lanes, so I could easily set all four of the sequencer lines to the different tempi I'd envisioned. Pretty much the same thing will work with them in CV/gate territory, since they have two channels of that for the pitch sequencers.
Also, since they have that third "drum" lane...which is nothing but clock pulses...you can feed that rhythmic sequencer to some Boolean logic, and get even more crazy crossrhythmic action.