Circulation Rules Editor - Invalid criteria cannot be removed from priority line

Criteria line of the Circulation Rules Editor contains attribute codes that are not currently recognized as valid and cannot be used in circulation rules (s, c, b, a). While these attribute codes should be removed from the deployed editor until their use if fully supported, attempts to manually remove them in the editor results in an error (see attached).

Expected results (acceptable short term): Staff users should be able to remove these criteria from the editor without error.
Expected results (preferred): The editor should only support entry of attribute codes in the criteria line that are fully supported in the construction of circulation rules and should present an error to the user if invalid codes are present in the editor when saving circulation rules.

Actual result: Invalid codes are present by default and cannot be removed without throwing and error when saving rules.