My experience with Cognito matches the author's experience exactly. I mostly used Auth0 in the past, but we switched to Cognito for a new project because it would be cheaper.
Don't like that email addresses are case sensitive, and now you want to change that? Sorry, you gotta create a new user pool from scratch--no way to migrate.
Don't like that email addresses are case sensitive, and now you want to change that? Sorry, you gotta create a new user pool from scratch--no way to migrate.