Maybe it's just the way I played and progressed, but while there's evil quest options at the camp, none of them felt like something I was given a reason to do beyond just evil for the sake of evil. And in general I don't feel like given a good reason to go out of your way to investigate the camp when your primary concern is selfishly seeking out a way to get the tadpole out of your head so you don't turn into a mindflayer. In my playthrough I don't think I experienced anything that suggested the True Soul business was anything more than a weird Mindflayer trick. I didn't encounter anything that would convince me they could be trusted or they had any solutions for me. If I missed something I would love to hear what I missed because I really want to realistically roleplay those evil quests.
