I've literally just bought a Beatstep Pro for this after realising i want more control than the Robaux LL8, just gotta learn the Beatstep Pro now! Its way, way cheaper to buy an external sequencer and the triggers give a good Thwack on drum modules, the LL8 does not and your kicks may sound a bit whimpy unless you boost the triggers through a VCA.

Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.