SQL Server Standard or a higher version should be deployed for the instance used by Veeam Backup & Replication instead of the SQL Server Express instance installed by default in large-scale environments. SQL Server Express has limitations on the database size, the amount of memory it can utilize, and the number of CPU cores it can use. For large-scale environments, these limitations can hinder performance and scalability, necessitating the use of the more capable SQL Server Standard or higher versions.