as weird as it sounds i would suggest doing like typeracer or something similar. the more muscle memory you have when it comes to where your buttons are the less you will have to think when you need to react. i can’t think of another game really where you need to have full awareness of at least half the keyboard to be able to use your potential.
Wow, i actually play like this too. Move with mouse, i use 1-6 and R, D, E , G and a couple mouse side buttons for abilities. What really helped me was having the G600 mouse because all of my modifiers are super comfortable for me to reach between all the side buttons and the 3rd clicker which i bound to Shift