Not real sure why you'd want to shoot an arrow that light in all honesty. Are you trying to get every FPS you can out of it??? What you gain in speed, you give up in noise and a touch of forgiveness. What kind of bow do you shoot??? I think with a shorter drawlength, you may be making things a little easier on the bow, but I'd not want to risk it on my limbs and cams on one of my bows. I shoot about a 415gr arrow, get moderate speeds out of it, and a nice combination of quiet. It's what I like, and works for me. I think you certainly would want to keep an eye on the limbs, and timing doing that though.

I suppose the other thing you could do is just drop the weight down around 65#, that way you are at IBO minimum, and see how that works for ya. You'd probably not loose much speed dropping that 5#, and you'd be a little safer on your limbs.