Double nutting is a good suggestion....And,yes, use Loctite. Read the lables. Some threadlock products will not harden, some will. Some require heat to break apart once cured.
If you haven't already installed the all-thread I'll suggest using bolts, preferably grade 8, instead. Measure the length of threads into the block of the stud you removed, add what you need to attach the mount and buy Allen head cap screws. Most all-thread, unless you purchased grade 8, is fairly soft stuff. Probably better than the Chinese items but not nearly as strong as grade 8. DO NOT USE STAINLESS STEEL FASTENERS. They're pretty, but have no extra strength
Tom