Requests for discovery and responses thereto shall be served in the manner provided by §1.28(d) of this title (relating to Service in Contested Cases) and should not be filed with the Hearings Division or Office of Administrative Hearings. Requests for issuance of a commission to take deposition shall be filed with the hearings officer with a proposed commission to take deposition only if the parties disagree on the scheduling or scope of the deposition. Depositions shall be returned in the manner provided in the Act, Texas Civil Statutes, Article 6252-13a, §14. Except for good cause shown, all requests for discovery shall be timely made prior to the hearing.