We are here at the same question as with the priorities for the electricity (accus have lowest priority, laser have highest), which was often been suggested - and also by some global changeable slider...
Despite from the fact, that it wouldn't bring anything good for the handling of the electricity (and I think also for the handling of this), I think this is really not a way we should think of.
Cause - and I think that is something important - how should that change be transmitted? How will the information come from that global configuration screen into the turret? I mean: Other games do that of course. Cause it is possible, it's a computer program. Everything is possible.

We are so used to that form of "magic global changing spreads throughout the game-world", that nobody cares. But for Factory I think this way should not be walked!
Cause if such a global changeable GUI really would exists I would say: Where are the radio stations to transmit that signal to the turrets.
Well. And here we have closed the circle: The answer to hook up that nightmare of 3000 lasers or more, is not to plug it into a circuit network, but to connect it to some wireless signal. And - as you might have read - that might come with 0.13. https://www.factorio.com/blog/post/fff-123
So that is in my opinion the way to do it right. If needed. What I doubt.
