The Nine and the Three

[Inziladun]

While looking back on what I believe was the first thread I ever started, I had another thing I was considering that is a bit far afield of that, but the mentions of the Unfinished Tales chapter The Hunt For the Ring there perhaps bring it in line.

Anyway, in that section, when detailing the Nazgûls' search for the Shire around the Gladden Fields and to the north, the Witch-king has the thought that the land of the Halflings might well be

....not far from the hated land of Lórien....if it was not indeed within the fences of Galadriel. But the power of the White Ring he would not defy, nor enter yet into Lórien.

Would not defy seems to imply that the WK knew for a fact that Galadriel was the keeper of Nenya, and that he chose not to challenge her. However, FOTR leaves little ambiguity that Sauron did not have firm knowledge of who kept the Three, though he had suspicions. Maybe that bit about the Witch-king was a mere slip on the part of Tolkien. It certainly seems that if the Nazgûl were capable of perceiving the presence of the Three, there had been ample opportunities to do so.
For instance, Elrond probably used the power of Vilya when he caused the Bruinen to flood. And the Nazgûl attacked Gandalf on Weathertop, so one would think that Narya would have made its presence known, if they could have felt it.

So I guess the question is, could the Nazgûl, being under the power of the Nine Rings, feel the proximity of other Rings of Power besides the One? If not, why not?