Notwithstanding any other provision of this subpart, the Secretary of Labor is authorized to perform any of the functions otherwise assigned in this subpart to the Under Secretary in any proceeding. The Secretary is also authorized to appoint as an alternate official any other officer or employee of the Department of Labor to perform functions otherwise assigned in this subpart to the Under Secretary or the Solicitor of Labor in any proceeding; except that:

(a) The functions otherwise assigned in this subpart to the Under Secretary and the Solicitor shall not both be performed by the same alternate official in the same proceeding, and

(b) The same individual shall not be appointed as both an Examiner under § 0.737-5 and an alternate official under this section in the same proceeding.