I think super heavyweight is a bad idea. HW is the best it's been in a long time right now. The last thing they need is the division cut in half. You will have guys jumping all over the place between divisions.
This is what turns off a lot of people from boxing. At least some of the people I have talked to. There are so many divisions and titles and guys fighting in multiple divisions that's its hard for any new fan to follow any of it. It's a mess.