Right now it appears that the Assign Permission is all or nothing.
We would like force the "Assign To" functionality to limit the list of users to only be in the user group defined.
Thus, if the workflow step defined assigning to a developer, the user list will only display the list of developers. If the workflow step is to assign to a QA Engineer, the QA Engineer would only have assign-permission to assign to another QA Engineer.
If would be even better if we can configure based on the user's group to specify which group of users should show. For example:-
User group A able to assign ticket to only user in group A
User group B able to assign ticket to users from group A and B