We are looking into installing Imaging Driver Update for August 2018 for ZEN2017U2.

Did anyone try it already?

Something I noticed in the readme:
IMPORTANT: It is expected that UEFI client machines will reboot once the first time they are booted after applying the driver update. This is done to enroll our company's public firmware key on UEFI devices as mandated by secure boot standards.

What does this mean for our clients? Does this reboot happen on already imaged devices or only to new devices which enter the PXE environment?