What lighted nock are you thinking of using. I tried the Luminock and the Easton lighted nock and both were heavy and did throw off my arrow. At 30 yards the excessive weight on the rear end of my shaft actually caused my arrows to hit 4" higher than the standard nock.
I switched to Nocturnals which are only 3-5 grains heavier than a standard nock and the difference in FOC and accuracy is minimal. I'm not sure but I believe Carbon Express has similarly weighted nocks.
There are a good many people that don't think you should use a lighted nock and some states that still don't allow them. But once I tried them and use them hunting I think that is foolishness. During first and last light there is no question as to where you hit your animal and whether you should back out or not.