I would not be surprised to learn that BG3 is going to herald a Psionics official release (assuming they finally settled on the subclass approach). I don't worry too much about using the psychic options that are just marked "Wisdom" but I am not touching anything marked with the tag "Illithid". I'm wondering if it is going to be analogous to overuse of Bhaal powers in the earlier games. If I remember right, that also caused bad stuff to happen.
In BG1 nothing bad happened, but in BG2 everytime you used the slayer, your reputation would drop by 2 points, which in turn, if you overused it, could possibly cause a bad ending. Solar's reaction to you after Amelyssan is dead is tied to your reputation and not your decisions made in the game, which is... a poor game design, but that game was made 20 years ago so welp, it can be forgiven for such oversights.

But so far, in the EA, it doesn't really matter if you use your tadpole or not, mind you, in both my runs I did make it a point to never use it, I did reload earlier saves to see all the dreams though.
I even made it a point in one of my saves to not let Omeluum, that friendly mind flayer in the Underdark, mess around with my tadpole, since after he does so, it's 'strengthened' instead of weakened and you get a special tadpole power akin to those you get from dreams. Basically, I found those shrooms for him, but didn't drink the potion. Yes I know, he gives/sells you a ring that blocks the tadpole from growing stronger and you from using it's powers, but still. Quite curious if that little encounter could lead to a slightly messed up ending. Oh, and that ring can also be pickpocketed from him.