国外のESRS/VEから国内のUnityを監視対象に追加する方法

ESRS観点では監視対象との疎通ができていれば問題はないのでその他の要件はご認識の通りです。。

Unisphere Help

Requirements for Centralized ESRSより

• Network traffic (HTTPS) must be permitted on port 9443 between the Unity system and the ESRS Gateway server. Also, network traffic over port 443 is required for ESRS functionality.
• The ESRS gateway server operating environment must be version 3.12.00.04 or later