Please display a warning message that the main app will be stopped meanwhile the restoring process (snapshot preview) is taking effect.
Snapshots can be restored to the original web app, a slot of the web app, or any other web app in the same App Service Plan. While the restore operation is in progress, the web app will be stopped. It is strongly recommended to restore snapshots to a new slot instead of overwriting an existing slot in order to prevent data loss if the restore operation is unsuccessful.
Snapshots contain both web app files and web app settings. You can choose to restore files only, or to restore the settings as well. All settings contained in regular backups are also contained in snapshots. However, some settings, like hostnames, certificates, and backup schedules, will not be restored with a snapshot.
https://blogs.msdn.microsoft.com/appserviceteam/2018/05/07/introducing-restore-from-snapshots-preview/

Thanks for the suggestion we are looking into it, will update once we have updates to share