You can use the below text mode filter in a User report or a User filter:
isActive=true
isActive_Mod=eq
licenseType=F T
licenseType_Mod=in
EXISTS:a:$$EXISTSMOD=NOTEXISTS
EXISTS:a:$$OBJCODE=ASSGN
EXISTS:a:assignedToID=FIELD:ID
EXISTS:a:task:statusEquatesWith=CPL
EXISTS:a:task:statusEquatesWith_Mod=ne
EXISTS:a:status=DN
EXISTS:a:status_Mod=ne
It has three components:
1. User is not deactivated.
2. User has a paid license that allows them to be assigned work.
3. No Assignment exists in which the User is assigned; the task's status is incomplete; and the User hasn't set the task to "Done with my part."
It can be used in conjunction with additional filters, if you need to focus on specific groups, teams, etc.
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