I don't know how the R-U152 Project operates, but we let people join the R-L21 Plus Project with as little as a 12-marker FTDNA test as long as they have an L21+ result from a reputable company: FTDNA, 23andMe, Ethnoancestry, Genebase, etc. They just email me the test results, and if they are L21+, they're good to go.
That is why you will still see some red R1b1b2s on our Y-DNA Results page. Those folks tested L21+ with some company other than FTDNA. We even have a few with the green R1b1b2a1b that shows they tested up to P312 with FTDNA but then, for whatever reason, tested L21+ with some other company, mostly 23andMe or Ethnoancestry.
Of course, I prefer that members get their L21+ from FTDNA. That way they show up in their FTDNA projects with the green R1b1b2a1b5 of the YCC Tree that FTDNA uses.