11.—(1) The Chief Inspector may at any time before he is notified of the date of the hearing of the appeal amend his reply or deliver a supplementary statement by way of reply.
(2) The Chief Inspector may amend any reply or supplementary statement with the leave of the Tribunal at any time after he has been notified of the date of the hearing of the appeal or at the hearing itself. The Tribunal may grant such leave on such terms as it thinks fit, including the payment of costs.
(3) The Chief Inspector may apply to the Tribunal to give directions as to any matter relating to the hearing of the appeal.
(4) The Chief Inspector shall send a copy of every amendment and supplementary statement to the Tribunal.