My concern is how it will affect the consistency of divination in ast's opener.
Because of how you can't gain a seal unless you or your target has already hit something, if the game fails to register that first seal, div will be off kilter from the rest of the parties buff window for the entirety of a fight. (unless you hold it til the next window which is equally terrible)
On top of that, to have div ready for your opener, the party would need to wait to let ast's draw come off cd, which isn't very common outside of an organised party
As far as controller issues, I can't say much. I'ma controller user (play on console), but i've never personally felt taxed by Sleeve draw
