Originally Posted by FCL.015 Application and issue, revalidation and renewal of licences, ratings and certificates.
(a) An application for the issue, revalidation or renewal of pilot licences and associated ratings and certificates shall be submitted to the competent authority in a form and manner established by this authority. The application shall be accompanied by evidence that the applicant complies with the requirements for the issue, revalidation or renewal of the licence or certificate as well as associated ratings or endorsements, established in this Part and Part-Medical.
Originally Posted by FCL.040 Exercise of the privileges of licences
The exercise of the privileges granted by a licence shall be dependent upon the validity of the ratings contained therein, if applicable, and of the medical certificate.
If I guess correctly, in the inside your question is whether or not undergoing a test (SEP reveal.) with a FE falls under "exercising the privileges of a licence".