I teach a lot of children with hyphenated names. By Y9 they’ve always ditched one half and are furious when anyone uses their full name. I’ve had some embarrassing moments with parents who still insist on the full Elsie-May or whatever, despite the fact that their child hates it. The same often goes for cumbersome double-barrelled surnames - by the end of school they’re just putting one on exercise books, despite what it says on the register.
Remember, names are for children, not for the parents.