If 18th century customers recognized that Oerter's rifles were of unusually high quality and patronized the Christiansbrunn shop on that basis--and other makers copied these superb rifles (probably the best evidence of them being widely known)--then I don't think whether or not Oerter profited from this work really matters? Oerter just chose in 1771 to operate in a different economic system than we are familiar with. But that doesn't have any impact, or at least none that I can see, on the fact that he produced high-quality rifles.
The fact that Oerter made no profit from his products--in 1760, 1766, 1771, 1776--is important only in that it shows that the previous explanation for the appearance of his signatures in 1774 & 1775 makes no sense. Oerter was not "working for himself" and would not have felt any more sense of "ownership" of his products than he had done before 1771. The economic circumstances under which he worked--he made no profit, the church "owned" the products he made--did not change during his entire time at Christiansbrunn.
As far as the "wide net for a small regional shop": maybe. But:
A. Other reasons than reputation/brand can explain how Oerter's rifles ended up in the hands of some of the men that you mention. It seems that the Baers had a personal connection to the Oerters; Shackleton did lots of business with the Moravians. It's easy to imagine similar things for others, Samuel Coykendall, who seems to have lived about fifty miles—and Aaron Hankinson half that distance—from Hope, New Jersey (founded, 1768), the last of the planned Moravian settlements. (Maybe research in the Hope NY Moravian records would reveal something. Anybody ever looked?) In December 1763 the Moravians gave John Jennings, sheriff of Northampton County, a rifle (valued at £6) from Christiansbrunn. There are lots of routes that a rifle could end up in somebody's hands besides that person seeking out that rifle at Christiansbrunn because of the widely-known reputation of the shop.
B. The Moravians were the most cosmopolitan/global group in early America--meaning that, far from "regional," they had extensive connections and networks throughout America and transatlantically. It is not surprising that their products would move beyond Northampton County--either because somebody at a distance had long-standing trade relations with the Moravians (Shackleton) or because somebody passed through Bethlehem.
C. On the other hand, if it is really true that other riflemakers began to "mimic" some styles that originated at Christiansbrunn: that's good evidence, it seems to me, that the quality of their rifles became widely known--at least among other makers (not necessarily among customers).