Currently it's possible to register several devices for a single meeting. The way this occurs is that there's no way to check if an authenticated user is using the registered device they initially registered. The instances where this could occur is if the user is refreshing the page several times.
The idea is that if we know that a user already has registered a device before attempting to register, it'll make sure that error "User has excessive device registrations" can never happen. It'll also prevent additional "ghost feeds" to appear (if my understanding of webex is decent) since it'll no longer timeout old device registrations, rather extending the lifetime of the existing registration.
Would you please provide a step-by-step use case for what you are trying to resolve?
What do you mean by “restoreDevice” and “register several device they initially registered?” How does this relate to a ”browser session?” Are you referring to a Webex Room device and the Room Resource Calendar while scheduling a meeting in the Webex Site Scheduler?