Sorry, not I.
Though I have been using soft limits to great effect.
@LarryM has posted a decent amount about limit switch wiring and there are a few links found on this thread:
Breaking homing switches - Uh, and lot's of other stuff
I also remember reading about using Hall Effect limit switches as “Hard Limits” for the Shapeoko 2 a while back and it had a pretty nice diagram, but I can’t seem to find it now.
I think you wire them in series for each axis to the same pins as the homing switches and wire them as NC like you said and then you tell the gShield these settings. When you wire them NC then you’ll definitely want to have them shielded and the shielding grounded so reduce noise as well as maybe putting in noise filters if the shielding isn’t enough. Sometimes a noisy AC line can cause the machine to trip into Alarm mode in the middle of a job with the switches are set as NC without proper noise preventative measures.