Can you add a free form text field to the role assignment section of a review?

One thing to note is that when using participant custom fields, they are only editable by the individual participants, and not editable by the review creator.  In cases like this where the roles are likely already known by the person setting up the review, it would be nice for the review creator to be able to set the participant roles instead of relying on the participants to go in & enter themselves.  There is a request for this functionality here.