This article explains how many devices can be upgraded simultaneously from the Conductor.

Q) Is there a limit to the number of SSR routers that can be upgraded at once?
Answer: There is no strict limit on the number of SSR routers that can be upgraded simultaneously. The practical limit depends on factors such as Conductor system resources (when upgrades are performed through Conductor), available network capacity, provisioning and Asset Sync performance, and overall operational risk tolerance.
It is recommended to perform upgrades in controlled batches to maintain stability and improve visibility.

Q) Are there any user-specific achievements or restrictions that affect upgrades?
Answer : No user-specific achievements or restrictions apply to SSR upgrades. Upgrade permissions are determined solely by the user’s assigned access-management roles and are not based on individual user identity or achievements.