If I'm being honest, the thing that I think whm needs the most right now is some sort of cooldown like lightspeed or triplecast. Something to allow for whm to be more mobile than it currently is. Ast has reduced cast time and lightspeed, sch has ruin 2 and whm has nothing really. I realize Aero 2 is an instant cast, but that's a dot and not really something to be spammed and blowing swiftcast isn't always an option. This tier has really highlighted how bad whm's mobility is (though I really do think that has a lot to do with the fights themselves). I know reducing cast times (like ast) has been mentioned, but I'm not a fan personally. I like my cast times to line up with the global cooldown, just feels better to me, but that's just my opinion.