The largest number I've seen is R-9 on a radiographic film.
The radiographer was worried about his charges on one weld.
We state in our purchase order specifications that a welder will be allowed two chances, amenable by the our inspector, at which time a new welder will inherit the weld repair.
We always inspect prior to PWHT unless the MOC dictates otherwise. Fortunately most of our PWHT is due to thickness not chemistry except on some alloy piping.