| Hmm...how long would one have to use DR strings in order to obtain a noticeable difference in fret wear? And wouldn't one also have to have a bass with similar frets, different strings and approximately equal usage in order to compare? Also, one would have to start with two new (or equally-worn) basses in order to have a well-designed test.
That being said, it makes sense that since DR strings generally have lower tension compared to the same gauge strings from other manufacturers, the overall pressure on the fret just ahead of your finger would indeed be less when using DR strings. Assuming you fret with equal finger pressure regardless of how much tension is in the strings you happen to be using, of course.
So, yeah, it seems like a reasonable claim. I have only been using DR strings for about 4 years, and I don't have any basses with other strings, equal use, etc. to compare. I have no measurable data that DR strings reduce fret wear by 50%, 5%, 0.5%, not at all, or if they are indeed worse.
But it seems like a reasonable claim. | 
