There is an F85SR builder who lives only a few kms from me who is building without vacuum bagging and many F82s and other size F-boats have been built without vacuum. I would not be surprised if more were built without vacuum than with vacuum. There is no doubt about it, it's quicker and cheaper to not vacuum.
I'm vacuuming because I wanted to build the best boat that I could build and over the years I've acquired 3 vacuum pumps.
As far as accuracy of your CNC Mark Hastings did our CNC work. He designed and built his own machine and does excellent work. I expect he would be a good person to answer your CNC question. I'll drop him a line and see what he has to say.