The presiding officer will, where practicable, issue prehearing rulings, acting on petitions for leave to intervene, delineating the issues, summarizing the rulings made at the conference, specifying a schedule for the exchange of exhibits and written testimony, the date, time and place of hearing and specifying a time for the filing of exceptions to the rulings. The prehearing rulings shall be served upon all parties to the proceeding and any persons who participated in the conference. Exceptions to the prehearing rulings may be filed by any such party or person within the time specified therein. The presiding officer may serve amended rulings in the light of the exceptions presented. Such rulings and amendments, if any, shall constitute the official account of the conference and shall control the subsequent course of the proceeding, but they may be reconsidered and modified at any time to protect the public interest or to prevent injustice.