For the Assignments standard system field, if you assign multiple users to one task (Which happens fairly often), when using Reporting for "Assigned to" the report will only pull in the task for the Primary Assignee (Person assigned first). Where we would want the task to pull in for all users assigned.
The same logic applies for Reminder Notifications as well. When the notification email goes out it notes who the task at hand is assigned to, which is always the Primary Assignee, which is misleading and causes confusion for the others assigned to the task, and they do not action the item thinking that the task is not assigned specifically to them.
The solution we need for these from Workfront would be to have logic that accounts for all users assigned, opposed to just the first user who happens to be assigned.
Please vote for this initiative as it is a major system limitation for all users of Workfront users.