What this study did was pretty much what I did when I built those ht15 and ht35 variance maps. They realized R1b1b2 has 2 main modals (what we've all known for years, but most geneticists seem to be stuck in a time warp) and that this undermines everything about Balaresque's analysis, which erroneously claimed R1b1b2 has a start-like pattern, which we know for a fact isn't true because SNP-testing shows the vast majority of Anatolian R1b1b2 is ht35, while most European R1b1b2 is ht15. The Morelli study "found" this (the time warp, again) using the marker DYS461, and showed that Balaresque's star-pattern is wrong. They mention that study frequently, it would seem their study is a rebuttal to Balaresque's study.
Except what is important about "HT35" (a term I wish we could quit using, since it is nearly useless) is that it is believed to be the ancestral form of R1b1b2. Thus the presence of a greater amount of P310- R1b1b2 would seem to be the mark of the older homelands of R1b1b2. Both so-called HT35 and so-called HT15 are M269+. They are not really two completely separate and distinct things, so I disagree with you about the usefulness of Balaresque et al.
Finding places that are almost exclusively P310+ ("HT15", another term we are better off without) doesn't tell us much about the origin of R1b1b2, although those with greater P310+ haplotype variance can tell us something about the origin and path of P310.
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