Fine control over plantation ... hmm. Overpowered, or just fun?
On second thought, since plantation is going to remove those resources anyways I don't think there's really an issue here. Most bloodmages would probably take the blood pools over the piety anyways and skip on plantation altogether.
Interesting thought about GG, though I think I'd thematically still prefer him to be a bit of a PITA for incoming blood-drinkers ... like making Cleanse simply remove existing bloodpools, since he has no use for them himself and it would help, uh, "straying" followers avoid dark temptations.
I feel you'd need some sort of exchange to make this work, otherwise we're still in the situation of "characters with sanguine can't worship GG". The Dracul->GG conversion option is already passable at best, and Bloodmages are giving up literally all of their class features
to join his religion. I feel you need to offer something, especially since drinking the blood pools before joining is already a suitable workaround if you absolutely need a specific boon.
I find all this casual joking about a Packmaster god who gives utility and hands out alchemy seals incredibly ironc
You kidding me? This is actually shaping up to be an interesting deity! If there's a joke dungeon introduced at some point, there should totally be an altar of the Packmaster.... hmmm... Secret Goat Level
Also, Bloodmage wouldn't mind worshiping EM, tbh, if for no reason then for a bunch more stacks of Greenblood.
Vine Form would also be a superb investment for them at lower levels, letting them get a lot of value out of tapping blood pools and enabling them to tackle really tough foes.