Oh my, I'm flattered
Anyway, my personal belief is that the Nazgul felt the Ring only very vaguely, more if it was on someone's hand currently. The Nazgul did not feel the Ring almost ever during the hobbits' journey through the wilderness. I have the feeling I was responding to similar question recently on another thread - remember the scene in Imlad Morgul when the Witch-King passes the bridge of Morgulduin and suddenly feels Frodo's presence. Khamul, of course (unlike WK), knew that the Ring was supposed to be around, and also was, as it was mentioned in the first post, more sensitive to its presence. Nevertheless, when Frodo was near (overhearing the conversation), Khamul concentrated on other things (the interrogation of Gaffer) and later, Frodo was further from him and also, there were more hobbits around, which confused the Nazgul: to what was said in the first post, I might add that not only in dark, but also in
loneliness they were strongest. I think the presence of many people could have disturbed their feelings.