So, as it stands now, Blood Magic for Spirit Shaman must be toggled on, then your SS casts with the higher DC—and gets the Hit Point drain—then, you have to untoggle the Feat in order to go back to normal DCs.
The untoggling is a step that can waste quite a bit of time in a fire fight, which may well get your little dude killed dead.
So, would it be possible, and not totally OP, if Blood Magic worked like a metamagic feat, in that you could assign spells the Blood Magic bonus, which also gains you the HP drain, then slot those spells to the Hotbar, directly?
Thanks for considering (if it is even possible).