Aww Hubert! I fell in love with him a few months ago, I love the meaning of “bright heart”, and the name itself is so lovably old fashioned and dweeby. I think it could be usable in the U.S., it certainly wouldn’t get much praise but that’s the price of an unpopular name I guess. I would consider using it, if they weren’t so many other names I prefer. I kind of love the nn Hubby, if it wasn’t a nn for husband haha.
The first time I heard the name was in the show Wind At My Back, about two brothers during the Great Depression, Hub (Hubert) and Fat (don’t recall his real name).
It’s also what I would name a giant draft horse, like a clysdale or a shire, if I ever obtained one :)