something ought to be done for level 10 blessing

[PvK]

10 is awfully close to 9, and does give you an extra +1 the level-4 blessings (and intrinsic magic), compared to 9.

I think it's just fine as is. There are reasons to go to 10... mainly, to actually use it as magic power (powerful battlefield spells made that much cheaper and more potent, extra summons, beating Astral-9's in Magic Duel, etc.).

PvK