Huh, you are right.
I’ve just noticed something interesting too, in the discharge curves.
It never goes above around 3,45V.
Seems like LiFePO4 cells have the same kind of discharge curve as most lithium ion cells, and therefore, the same property of having the lowest internal resistance during discharge rather than at full charge, and so, as I’ve tested it(but never posted), there’s almost no difference in capacity between 4,13V and 4,20V.
However, that effect seems to be amplified by a large margin with that chemistry, losing almost no capacity until below 3,4V charging voltage.