Blocking AD Logon Scripts

When starting a PoC or new VDI deployment, in terms of group policy, I want to isolate the new environment as much as possible.  I don’t want any existing user and computer settings applying.  Often, the project will involve optimization in this area (in this case the introduction of User Management products such as Citrix WEM or VMware UPM). I will block policy at the VDI OU level and create a loopback policy (REPLACE) so only settings from one place are applying.  I may well have to tackle enforced policy here too. However, this does not take login scripts defined...