My Solution to Atma Grind
1) go to Display settings and change to "borderless windowed"
2) go to sound settings and turn on "play sounds when window is not active"
Now sit at a boss Fate Event area alt-tab to something u like doing example: read manga, watch a movie or just surf aimlessly an wait for the fate commence sound, alt tab over kill the boss then rinse n repeat.
I refuse to run around like a headless chicken anymore an get angry. So i'm now playing this game like a second rate facebook game.