Why can I boost but not transfer

I understand queue size is an issue. But I already have one character in benediction. Why can I not transfer my max level over, but I can boost a character on the server. They both cost money you still win in the end. I just feel boosting the same class I already have is a waste.

Blizz pls my characters are stuck and I can’t be logged into more than 1 at a time :slight_smile: