FWIW, I understood what you were getting at. To manually run one out on a Bridgeport takes a good bit of time. However, if one programmed it in on a decent 3+ axis cnc mill or Bridgeport conversion, the time drops immensely. Even a good multi-tool readout system would cut the time down after the first one were done. Especially since these are aluminum parts (any idea of the metallurgical composition? 6061, 7075, etc?).
What I was getting at though, is the equipment needed to run multiple items in a "party amount of time"is not usually found in someones garage. I have everything one would ever need or want to do this and would love to host. The issue is that I can't have a group of people in my shop building firearms. Imagine the legalities of the situation. What if someone got hurt? What if one of these lowers found it's way into the hands f a criminal and used in a crime? It eventually gets traced back to me and then a non FFL holding machining company manufacturing and distributing firearms. Best case scenario, I'd lose everything. Worst case, I'd be in jail.
Heck, the same thing could happen from a homeowner standpoint. Your insurance company does know you have industrial machine tooling being used in your garage, right?
I see your point. There are some concerns for sure.