429.29. Cases in which the subject-matter in dispute is substantially the same or which could suitably be combined, whether or not the same parties are involved, may be joined by order of the president or of a person designated by the president on the conditions he fixes.
An order made under the first paragraph may be revoked by the board upon hearing the matter if, of its own initiative or at the request of a party, it comes to the conclusion that the interest of justice will be better served by doing so.