TOTAL
30
Yes, I can see how the device determines the workflow (and also the genres). Also, sticking to kit adds to a sense of continuity.
Toggle is better for muting indeed, and fill has its other applications. That would mean ‘shiftless’ midi kik mute at the cost of a track. However, for the genres a4 seems predestined, isolating kick is not a priority 
Following guys’ advice above, I will have a look at how you develop songs out of curiosity because I was looking for more of a techno-in-a-box device.