Your question is a good one. I once bought a new set of strings (can't remember the make) for my 35" Cirrus 4 and the outer winding on the E didn't quite reach the nut!
I have a Cirrus 6. What I've discovered is that most strings with silk windings on the top fail to clear the nut on the B string. I have approximately 1/2 inch of silk protruding into the first fret. I have not noticed any detriment to the sound while playing it though.