Thanks for the inquiry regarding adding a Roku devices to a single account.
If you are looking to add a large amount of Roku devices to an account, we would recommend creating multiple Roku accounts and designate them to groups such as floors, room numbers, or whatever you feel is most convenient.
We hope this provides clarification. If you have another other inquires in the future, please don't hesitate posting in the Roku Community again.
Roku Community Moderator