I can't look at, or think of,
Estelle without thinking of my Uncle
Estelle. I knew him (vaguely) as a child, but often heard references to him.
Anyway, his name was pronounced ES-tul. I have no idea why he was given this name. His many brothers had typically masculine names (for the times).
So I really can't give you an opinion of
Estelle as it typically is used, for a girl. But I thought the use of
Estelle for a boy/man might be interesting.