I can confirm from the ground -- the concourses are not attached in any way. You have to go through the C/P for your concourse. Not sure about C/P A, but I know that C/P C also has NoS.

Out of 10 trips through CMH:

4 Self Opt Out (see below)
3 Opt-Out with Freedom Grope
3 NoS Closed

My "Self Opt Out": I dart toward the WTMD, with a purpose, as there was never a doubt in anyone's mind that I was going into the NoS. It's especially good when the TSO is looking at someone else or the other way Don't be super obvious, just be quick.

Any actual opt-outs have been handled very well. The TSO's at CMH, as a whole, are close to the best I've encountered around the country.