How should you ensure that all session hosts deployed from Image1 are onboarded to Microsoft Defender for Endpoint?

The correct approach is to add the Defender for Endpoint onboarding script to Image1 and configure it to run at first start. This ensures that every new session host provisioned from Image1 will automatically onboard to Defender for Endpoint upon its initial boot, providing consistent security coverage. Running the script and then sysprepping would onboard the image itself, but not necessarily the individual session hosts as distinct devices. Creating an MSIX package is for application delivery, not host onboarding. Creating an automation task for the pool would be a reactive measure after hosts are already deployed, not a proactive part of the image.