Since I already own a minilogue I think I'd just be going for one sound from the modular, perhaps later on two.
If I get a semi-modular synth the sound will start there and once I have enough money to get a second sound source (with VCO/VCA/envelope generator etc etc) I will have two sounds..
Anyway my beatstep has 3 sequencers, two for synths (1x minilogue, 1x modular) and one for drums. I would be using my MFB Tanzbär for drums and perhaps my volca beats. So yea really what I'm looking for from my modular synth is something that can function as a pad ór arp ór a bass, but not simultaneously. I can make either sounds from the minilogue aswell and atm I'm still running from Ableton Live so I could always use soft synths or samples for additional sounds.