Is there a procedure that can round out my butt more without adding to it? Not interested in a BBL, just some contouring

Yes.  Liposuction above and to the sides of your buttocks will make your buttock definition much better and rounder.  It will not increase the size of your buttocks, but reshape it.

I agree that adding volume to your buttocks is probably not needed. I think your best option is liposuction of your love handles and improving the transition from your waist to your buttocks.
I suggest having several in person consultations where you can discuss what you’re trying to achieve and what can be accomplished in greater detail.
Best, 

Matt Hagstrom MD