Yes.
For me it is:
Computer —> Documents —> Starcraft 2 —> Accounts —> 13800***** (censored, i don’t really know what is it for, I have 2 folders here, I just chose the one that contains my usual replays) —> Hotkeys —> name of your hotkeys template, for me it’s “0_Default”, “Coop” and “1v1 Protoss”. I am not sure if you can edit default.
After opening the file in notepad, you edit “TargetChoose=LeftMouseButton,T,F,V,M,Z,S,D,E,C,A,G”
line, as mentioned in the video sent. I do not know if it is saved when you change your computer, though.
It is “legal” to use during most of official and unofficial tournaments, Maru was using it for “movement” command during one of WCS, and I am sure he had it for different keys as well (like snipe). So it’s not “cheating”.
Have a nice day.
#Edit: Fear the man who has “S” button from Stop command on rapidfire!