Tadpole actualy feed on brain power and you become weaker ( lore) . So thats out the window .
Tadpole in BG3 grants user special strenghts (like mind trick thing) and by succumbing to its power seems to have some form of consequence.
Those are not usual tadpoles and they have been created for the needs of BG3. What it exactly encompasses remains to be discovered, those there are some interesting bits and pieces spread as across various interviews.
