If it's like the v8 Auto Rocket Launcher, it fires normal rockets at a slightly faster rate while you hold down the mouse button.
However, this new model looks very nice.
Alt fire for triple burst please 
That would be a simple edit of the current states the RL uses. Even I could do that...
I think Kaje is going for something bigger.
I do like the triple burst idea, though. Maybe, use every 10 or 12 seconds?
By the way, can Trader please tell everyone how much of an idea we have of what is coming? I don't think he made it that clear.