Welcome to the Roku Community and thanks for posting regarding your inquiry regarding accessing accounts with your devices.
Unfortunately you will only be able to access one Roku account at a time. If you would like to access all of your Roku devices including Roku Smart Home devices, you can always link everything to the same Roku account.
We hope this provides some clarification. If you have any other inquiries in the future, please don't hesitate posting again in the Roku Community.
Roku Community Moderator