Does dou provide a test environment per customer (aka Sandbox) to test configurations and settings?
In your main account you can use policies assigned to test applications and groups to validate your configurations before rolling them out organization wide. There’s no limit to the number of applications you can create in Duo.
Duo’s personal edition is always free. Some customers create a separate personal account to test global Duo settings (configuration items that can’t be restricted via policy or group assignments).