Did you give the tech permissions to change any product policies?
As a test I setup a permission set with permissions to the following:
- Server tasks
- System Tree access
- VirusScan Enterprise 8.7
After that I was able to create a task that runs the duplicate systems report and assigns a VSE policy to the results. I noticed you gave the Policy Assignment Rules permissions which is actually used for user based policies. If you want the tech to be able to modify the policies for VSE 8.7 for example you would have to give him permissions to VirusScan Enterprise 8.7 in the permission set.