Duplicate Performers in Expressions

When setting performers using expressions, not equals compare will not work when the same user is in the array returned from the expression multiple times.

Example task 1 is done by user A , task 2 is done by user B, task 3 is done by user B, and task 4 cannot be assigned to any user that has done task 1,2,3. The assignation expression for task 4 is User Id - Not Equals - Expression -[A,B,B] and the user B is still automatically assigned to task 4.

Workaround is to get distinct values in the array but would be nice to have it just work without the additional check.