Maybe S&W should simply mass manufacture the guns, and then send to various "finishers" who do the final fit and finish and function check QC. Then let competition between the multiple finishers compete for level of fit, finish and price. Some finishers will do minimal work and function test and they would sell for the least amount. Other finishers would be truly custom including trigger jobs etc and would be top dollar. Others will fall somewhere in between.

Just a different supply and distribution process rather than direct S&W to FFL. Sure it might add some costs, but the public and the reputation of the finishers will establish themselves and the buyers would have increased confidence in the quality, and someone to go back to if they find something amiss who has a direct motivation to make the customer happy so as to not harm their reputation. The internet is instantaneous with both praise and complaints. They cannot afford to have too many complaints or they may not be in business long.