I wouldn’t be opposed to a gaming mouse with extra buttons. Back in college a gf gave me a Razer mouse with a full numpad where the thumb sits. Was absolutely amazing for games with commands tied to those. Having something like that as a vertical mouse would be perfect. The only problem I see is when I click, I instinctively press my thumb into the mouse for stability. I trained that out of myself for the most part, but that could cause me to accidentally press a button when I didn’t want to. So they’ll have to be mindful of that when designing one.