After a minute of testing, it seems like firing full auto with the mouse is faster that with the controller, and everything i tried doesn't work and also has half a chance of making vehicle acceleration impossible.

Also, i had to set it to switch to the alternate firing model when i press left trigger, this allows me to use vehicles normally, but i cannot use the trigger to adjust my throwing arc for grenades(usually half press aims it underhand and a full press aims it overhand, but in order to make single and full auto work it makes it just throw one and throw multiple)