If putting the tadpoles into your brain, with all it's possible negative side-effects, isn't addressed really early in game through a npc/book/cinematic, this is a horrible decision. Just from the ui look alone, with it's black tendrils covering your brain, it feels like this will have big ramifications and the incentive to go "bad" with these extreme good bonus abilities is massive. The vast vast majority of players will have ONE play through not multiple to see different outcomes of bad/good/neutral play-styles. This might ruin the games overall experience for a lot of players if there isn't a counter incentive for the tadpoles in your brain or a huge red letter warning. Furthermore an dialogue option 30 minutes before the games ending to make it all undone and just remove the brainmaggots without any consequences would be the worst path this could take.
I swear to God, if they pull a last minute "lul, don't worry, none of your choices over the last 80 hours matter, you can just undo it all. Spent the whole time using tadpole powers? Didn't touch a single tadpole power? It's all the same! don't worry!" I'll be annoyed.
