It's funny you should mention that, Acturus. I just had an experience where I setup my Limbus group by dividing it into small parties so we could multi-zone. My group consisted of WHM, BRD, MNK (me), MNK with BB, WAR, BLU doing NE Apollyon.
So we get to the zone with monkeys and Gigas, and as luck would have it, we have to kill Cronos to get the portal to open (only vulnerable to magic damage). I'm like, "No problem, this is why I chose two of us to come on monk. The plan is we both Formless Strikes, 2hr, then hit the SP chest and do it again." The other monk (the one with BB) says, "Uh... I don't have that merited." This lead to a moment of stunned silence from me, just 'cause I figured since he had both a BB and more than one Usukane piece, by now he'd have unlocked it. (Even situationally, going from being able to deal 0 to being able to deal 75% of your normal damage is an infinite improvement for only 3 merits and one lost upgrade, right?) I didn't want him to feel bad (and I felt dumb for assuming), so I told him not to sweat it in party chat... and then sent him a private /tell asking if he could consider unlocking it to help us out. :P
Solution: I Formless-ed, 2hr'd, then the bard 2hr March, March-ed me for an essentially 2nd round of fast damage, then we hit the SP chest for a rinse and repeat. (The BLU set some breath spells and got in there for some damage and I think the WHM might have popped a Solace-pumped Holy in there too.)
So we won the run but it was much closer than it should of been (with something like 3min left at the end).
Moral of the story: There is none, but I'm rating you up for unlocking this. :P