[nineplay]

My number one concern is predictors so I'll address that part.

You can turn off "chat" with anyone other than your child's friends. You're kid can be in a group chat with their friend and other strangers, which I'm not delighted about.

Downside #1 is that anyone can send a friend request and your child can accept them. Whenever I go into my kid's account I do a friend review - "How do you know this person?". My child also always has a dozen pending "friends" requests from as-far-as-I-know complete strangers which I decline for her.

Downside #2 is that Roblox can have odd restrictions if "chat" is turned off - you can't give your pets names "Adopt Me" for example.