The biggest difference between the two attempts is that in one you were going for uberman and in the second you were going for everyman. This, I suspect makes a bigger difference than the use of 6 versus 12 naps.

This, and the fact that my body probably sort of remembered how to do the REM naps from last time. I accidentally suggested that the success itself was solid evidence. I don't believe it is. What I meant to do was simply cite my own experience with this stuff (in addition to my research) which strongly suggests more naps (well-spaced) would not have any negative physiological effects, and would have a net positive psychological effect (because you really want to sleep, so it's nice to let yourself sleep more often). Therefore a good idea.