I would like to see this really small, but in my view important changes to the gameplay.
First it would be the mysteries hotkeys, why not go with W,A,S,D as that is a more known pattern to most of PC gamers worldwide, it would just feel more natural.
Second add a *on or a hotkey on world boss, maybe the Space key, that will toggle auto run to the boss. A lot o people ask for an auto run function for world boss, its rally boring to run to the boss after every death specially if you dont have a big monitor, because the UI gets really cramped with stuff.
Add a *on for turn by turn result instead of a x2 battle speed only on Ranked Battle, that we can activate if we want to save time, after all before the action even starts the AI already knows the results, so it would just skip the animations and show the damege and status only each turn.