I started testing straight away when I saw this. I'm already running into issues though.
- It won't let me use email address in an update rule, I get an error telling me i'm not allowed. If I want to create a data card to map to a contact this is pretty important.
- After creating an update rule, it doesn't appear in the list of update rules as an option when searching through program builder. I made sure to also include it in the program details to say that data cards from this set will be used.