I believe story consequences was semi-confrimmed allready by some datamining ...
But i never heard about any for those who refuses to use the tadpole. O_o
Maybe only if you count that Ring you can Buy from Omellum?
If you dont use your Tadpole, you get free psyonic protection, and dont have to sacrifice any ability (maybe except that one you get from that potion ... but im not sure if that can be avoided too?)
I still dont understand why cant we change Race for our hirelings.
Lets us play Githyanki as racist as they trully are!
