Thanks to all for advice and help. Warkton is correct about the dome nuts not being an issue in this particular case, so I'm quite happy to use loctite on my slack stud.
There is no 'shear damage' whatsoever so I'll happily use the stud that I have. Although if I recall correctly I replaced it with one from a Spanish hub when it initially went slack.
Anyway thanks again to the knowledgeable LCGB membership for sharing their experiences and know-how. It has helped me once again.