Ability to add an authorized sign off person to a check form (as a one off)

All our check forms are set up with the applicable sign off personnel - generally Examinee, Examiner, Head of Training and Checking and an admin person. However, when the Head of Training and Checking is the examinee, they should not be then also signing the check form as the Head of Training and Checking with out some oversight. Would like the ability to add another name to individual check forms, so that in this example before issuing this check form for sign off, we would add the Chief Pilot as an additional sign off person. Similar to the ability to add an extra sign off person for an audit