I set up #4's keybindings in game like this:

Move Backward - Ctrl + Down Arrow
Move Forward - Ctrl + Up Arrow

Then I just programmed the G15 key to record the multiple keystrokes, so yes, it is more than 1 keypress, but there are no pauses or delays. Because the same movements are keybinded to the alts for their strafe left/strafe right. So they all move at once and finish at once.

As far as I know and have researched, this is legal and there'd be no reason it shouldn't be.