Consistency in filtering roadmaps by "persona" type custom fields

When I filter a roadmap by a "persona" type custom field, I only want to see the selected personas.  Today, if I have a feature that impacts multiple personas (example: Rad Tech and Service Engineer) and filter just by Service Engineer, The Rad Tech persona is still listed in the row because both the Rad Tech and Service Engineer share features.  What is confusing about this setup is that it is inconsistent with how the "tag" type custom fields work.  I have a "tag" custom field to specify the product channel - mobile or desktop.  Even if I have a feature that will be deployed via both mobile and desktop, when I filter by just mobile, only mobile is listed as a row.  See attached for screen shots with additional details.