Right. There's no enforcement of visa itineraries so long as your first one has valid flights & hotel. After that, you get 10 years of multiple entry with no required itineraries. I just brought it up as a point, that Xinjiang is not a place you would normally be going. People seem to assume that Xinjiang is just a normal crossing into China that has heightened security. That's not the case at all. You would never accidentally end up there on a trip to China.
Most of that area is covered by mountains or desert, and there are only about 22 million people living there. The economy also isn't terribly developed (although IIRC it's the fastest-growing among all Chinese provinces) and it's not exactly popular as a tourist destination.
That doesn't mean there's no reason to ever visit, just that there aren't very many more reasons than for e.g. visiting the neighboring Kazakhstan. Most people crossing the border and getting subjected to the surveillance are probably ethnic Kazakhs living on either side, visiting relatives on the other.
In this specific case a single entry visa was used. The visa paper in the passports doesn’t show the itinerary stated in the visa application. Also all itinerarys and the flight tickets were made with either booking.com and immediately cancelled or with a fake flight ticket generator. Worked like a charm..