I don't think it depends on the audience size, BTW.
Well, I did reference to the audience size, because in front of thousand of people, (in my head) I think you have more chance to play a structured setlist of songs... and not only do half a hour of blues jam with some friends and few drunk people in a bar (well, you get the picture

).
I might be wrong, but people who wants more than 4 stomps are probably the ones who think about their Rig and ideal Kemper Foot Control like a traditional pedalboards, with half a dozen or more of stomps pedal (maybe 2 different drive, a comp, octaver, wah, flanger, phaser, chorus, delay, boost, etc...).
Of course, there's almost no chance to use all of them in the same time... that's why I like the approach of the Line 6 M13 (12 stomps, with 4 in the same time, with a very simple layout). I just don't know how good or bad it could be... typically I don't like much Line 6 (sorry

). But if the sounds is good, it might solve some problem and I might just use it with a Nova System (in the Kemper Effects Loop).
(I saw the new Vintage Revolution PedalPro, but the pedalboard looks like a crap and it's way over-priced... but the concept is nice to have 14 analog pedals).
In the other hand, it would be stupid to not use the Kemper for its potential for the stomps and effects...
Just thinking out loud
Phil