Is there a way to duplicate a "template" sheet with existing Supermetrics queries into 10 new sheets (with different respective Facebook ad accounts)?
Could I hypothetically create a GSuite script that would create the new sheets and then write onto the "Manage queries" sheet?
Any other options?
If you mean to copy the Sheet file as a template - you can use this feature to do that and switch the accounts being used in the queries:
If you mean to copy the queries into another tab in the same sheet file, you can go to the SupermetricsQueries tab (if hidden, go into the same menu shown above and click "Manage queries"). In there you can duplicate the query rows you want to reuse, update their Sheet Names and range addresses in the appropriate column, and delete the Query IDs (<-very important step!). You can then refresh the copied queries to generate new IDs and edit them as any other query to change their account settings.