MSI make the ring voltage entries in the BIOS turn red above 1.2v. Guess it's as a warning but it can be ignored (not too much though).
Comparing what you've achieved with your chip, to mine (yours is better, requiring less voltage to run at 45) - your ring voltage is actually a bit too high at 1.265v for 42 multi. And you should, in theory, easily get away with 1.2v for ring at 42 multi, and possibly less. It would also shave off a few degrees at the same time.
My chip needs slightly above 1.3v Vcore for 4.4GHz and near 1.4v for 4.5GHz, for total stability, so I don't bother (other than in benchmarks now and then) and run it at 43 or 42 most the time. But it can do 42/42 no problem with 1.2v Vcore and ring. That's why I expect the ring on yours to at least be capable of that, if not better.