WHY would you ever change the cast time for AST?

It'd be a hellishly clunky mess with this in place, with the ridiculous amount of OGCD weaving it has, especially with the cards.

I can't imagine its current opener on a 2.5s cast time.

The cast time was changed because ASTs damage and and playability were suffering due to insane amounts of clipping. The reason WHM and SCHs don't require this change is because they have considerably less things to weave (in WHM case) or some other means of weaving.

Please don't give the devs any weird ideas, AST's clunky enough right now with its current card system, it doesn't need this kind of sucker punch.