As many as it takes to reach a fully functioning release candidate version! It’s pretty obvious that C7 was a premature release in order to iron out any serious flaws in common coding that could have cause them major embarrassment if they’d release their flagship N6 at the same time 
Let’s just hope that they haven’t broken anything else by implementing the fixes in this release and that they’ve convinced the new captains at Yamaha to give us a modular consumer level version of Nuage for all our pains, a 16 fader version (coming in at a price point somewhere the the old CMC series and the cost of the iPad) with an option to add another 16 would be just right eh? Especially if it was a rack mount using 19 inch monitors and was able to fit into a nice desk top piece of of furniture 