Verify we check for insiders via registry

[PipeItToDevNull]

Once a policy has been set, restart the device to activate the policy. Then, to confirm that your policies have been set correctly, go to Settings > Update & Security > Windows Update on one of the targeted devices and select View configured update policies.

You can also check this key in the Registry Editor on the device:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate Devices set to receive an Insider Preview build show:

BranchReadinessLevel = 2 (Dev Channel), 4 (Beta Channel) or 8 (Release Preview Channel)

ManagePreviewBuilds = 1

https://docs.microsoft.com/en-us/windows-insider/business/manage-builds

[PipeItToDevNull]

We check HKLM:\SOFTWARE\Policies\Microsoft\Windows\PreviewBuilds\ but not BranchReadiness

[PipeItToDevNull]

Enable or Disable Windows Insider Program Build Settings using a REG File for Version 1709 and later

The downloadable .reg files below will add and modify the DWORD values in the registry key below.

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate

ManagePreviewBuilds DWORD

(delete) = Enable 1 = Disable preview builds

ManagePreviewBuildsPolicyValue DWORD

(delete) = Enable 0 = Only disable preview builds 1 = Disable preview builds once next release is public

https://www.tenforums.com/tutorials/63585-enable-disable-insider-build-settings-windows-10-a.html

[PipeItToDevNull]

Not all insiders have keys at all, this is moot