Wondering if joining ATG reduces the scope of my moving flexibility.
Depends on the team. You may have one or more of manager/team/design/ coding interviews or previous design/code reviews.
No, non-ATG orgs expect people to deliver, because we all know ATG people usually don't deliver
Sounds odd. You wish to move out of “Advanced technology group” to ... what? “Less advanced technology group”? But each one to their own.
I’ve heard that it’s not easy