First of all we need Shift as modifier. I dunno why you can use Alt and Ctrl but not Shift, it’s just so stupid. We use Shift since wow vanilla in 2005 and here we have to adapt or use 3dparty tools because, let me guess, of the usual tech limitations?
Also, we need a secondary keybindings set or make every character have Its own. Even here, it’s something that every game has since 2000s. Characters have different ways to use their special abilities and I’d like to use different buttons, for instance I want non targeting skills, like buffs or stances, on my mouse, but I want targeting skills like attacks, blink, etc on my keyboard.