I love them conceptually, but I also agree they shouldn't be afraid to experiment more. The moment I saw Chemist had infinite free revives, or knight having 90% damage mit I was blown away. It's cooperative, it's an isolated place, we're not competing with anyone to worry about balance!
I wish deep dungeons would do something similar aswell, just experiment, let us become for atleast short time in a restricted place be ridiculously powerful or make really fun combos!