excuter2 lite plus- LED on external switch question?

What the hell is it used for? Im really interested in getting that chip because of the external switch feature, but if the led lights up a lot then it would seem annoying to me.

I have already installed a Chameleon chip on another box and the internal LED on that chip shines pretty bright while the box is powering up and while sitting in the Evox dash.

If anyone already has this chip set up, could you please tell me when it lights up?

I also noticed that System-mods.com have temporary run out of the chip, could anyone tell me of a good US site the that I can buy the chip from.
Thanks