Add Assignment - Remove action for End User, but allow automation

http://community.landesk.com/support/docs/DOC-3633

I have looked through the above document & ran the script on SelfServiceGuest for Add Assignment, but all it seems to do is disable the "Execute" privilege on the Add assignment function.

With "Execute" disabled, when an end user selects a category with an auto -assign function, it dumps out with an error:

There has been an unexpected error. Click Continue to return to the previous page.

Authorisation failure. User is not authorised to perform Create operations on the IncidentManagement.Assignment class type.

When I enable Execute, it does allow this to work, but then it also enables the "Add Assignment" action when viewing the tickets.

Has anyone been successful in altering this so the Add Assignment function is not visible for the end user, but still functions when auto-routing by category?

I am on LDSD 7.6.2

Thanks!

-Dave