You would think so, 112.
I went, with RB, to a property to meet Cadent for them to do a dead test, same as OP scenario.
The Cadent guy, I think he is the one that lives at 5 BR, said he wasn't able to test it, as there is no valve. Doing so would release gas into the environment (empty house) ,and partially screwing it open would break the seal. All very true. I said about repasting the newly exposed thread, and he acknowledged that that is what most privateers would do.
RB asked if I could "just do it". I said that I could, and risks were minimal, but he would need to issue an actual job with the specific work required. He would (as I know that you would expect) not do that (!).
As a footnote, the pipe was about 6 - 9" off the floor, about 2 or 3 feet from the corner, so suggested that it be boxed in as a platform. Eventually, the pipe was boxed in, but literally, so instead of a a black iron pipe in the way, they know have a weird looking plywood square tube sticking put of the floor. But, as they say, not my problem.