This has been my question from the beginning, and this recent info from Larian does nothing to help me understand things better. They say that thre will be "costs," but that can mean anything, including negligible costs that players can easily shrug off in return for what are clearly huge benefits. But even this doesn't really get at the point, which is what benefits does one get from NOT using tadpole powers? I still very strongly suspect the answer will be the same glib answer some here have offered, which is: You lose out on huge benefits, get NOTHING meaningful in return, but get to have a nice brain free of tadpole corruption. Yay! How cool is that?!
Well they obviously won't spoil the game for you here by telling you what the precise consequences are but we did get one bit...it seems you can go all in and still save the forgotten realms, which is a good ending...though it might cost you your companions and they might abandon you or force you to kill them and so on. But it seems that going all in on tadpole powers doesn't lock you out of good endings entirely.
