Too often people have expectations that are much greater than a duplicator, man or machine, can meet. Time, quality and price are hard to get all in the same place. If you want it fast and cheap do not be surprised if it is not that good. A duplicator is only as good as the pattern and the operator and some stocks are a real pain in the butt to cut. Most semi inlet stocks are 90%, a few might be 95%. But it seems like too many really want 99% for 90% prices. It is not going to happen.
I bought my own duplicator, a Gemni, spent a lot of time and money upgrading it and learned the hard way. It is a lot easier on the video than in real life. One minor slip up, one little area on the pattern with a blemish, one soft or extra hard grain area in the blank, one hidden hollow burl and hours of work is ruined. Half of the battle is in having a clean, solid pattern that is well mounted in the machine the other is experience. If you cut a few hundred stocks you will learn all the tricks needed but there is no shortcut to experience. If you do not believe me I have a few ruined semi inlet blanks you can look over.
Gun stock duplication is a for profit job. Time is money and it will take three hours or more to cut a blank, add another to mount it correctly and to prep the blank. Figure four to five hours for custom jobs maybe less for a in house pattern. Man and machine should be worth $75.00-100.00 an hour. So most semi inlet stocks are made on a multiple spindle machine. That is why many duplicators do not want custom work. It just does not pay enough. It only pays to run multiple blanks at a time. That or you end up getting about ten dollars an hour for man and machine. That does not even pay for sharpening the cutters. If you like to try there are always a few Terrco duplicators on Ebay.
So if you send a stock to a duplicator that is not a standard item for the duplicator you are rolling the dice. Better to pay $300-500 for a 99% blank than $100 for 90-95% blank and hope for the best. If you can afford it my advise is to get the best duplication you can afford not the cheapest. Plus a 99% job will take you a tenth the time to fit and finish and your time must be worth something.