If I misunderstood you, I apologize. When you said "In CA for mfrs. to give up on that state Barrett style would mean those citizens in that state are to be left in the lurch with nothing but sticks, stones, and used market guns." I understood you to mean that LE would have guns but other citizens would not. My thinking is that if all manufacturer's refuse to sell, including to LE, then sooner rather than later the CA legislature will come around, as politicians are very fond of being protected by heavily armed police while not caring about the rest of us.
And, when you said "I hope mfrs. do not go the routs of STI and instead choose to comply _and_ actively track results of as much as related to future crime reduction (crimes actually solved by this means) and to later lobby legislature as a coalition to in the future end this requirement." that you meant that if firearms makers gather data that shows that the requirement solves few, if any, crimes, that the politicians will be persuaded to drop the requirement. That's why I responded that antis have never cared about facts, as the facts have long been clear: gun control doesn't work except to disarm law-abiding citizens. Anti-gun politicians don't care. They have an agenda to push, facts be damned.
As to makers complying and thereby reducing the # of guns available on the black market, that's bunk. Criminals will get guns no matter if it's legal to sell them or not. The only people penalized will be law-abiding citizens.
The answer is not to go along w/ the anti's wishes by asking "how high?" when told to "Jump!" by the state legislature. The answer is to beat them at their game, and telling them "You won't let us sell guns to citizens unless we comply with your laundry list of requirements, but you want us to sell to your police forces guns not available to everyday Joes? I don't think so. This is a free country, and we are exercising some of that freedom in this fashion: Take your "list" and stick it where the sun don't shine. Go jump in a lake while you're at it. We will no longer sell any products, from holsters to spare parts to weapons, to any law enforcement agency or officer in your state until such time as you get a clue and honor your citizens' right to self-defense by removing all your illogical restrictions on what your "serfs" may buy."
If Colt, Armalite, Savage, FN, Ruger, S&W, Glock, Springfield, H&K, etc. all did this, and CA agencies saw their weapons becoming unserviceable while criminals continued to arm up, the legislators would feel heat like they've never dreamed of.
Idealistic and unrealistic? Probably. But, it's better than the alternative, IMO.