If a direction to confer is given under rule 31.24(1)(a) before the expert witnesses have furnished their reports, the court may give directions as to--
(a) the issues to be dealt with in a joint report by the expert witnesses, and
(b) the facts, and assumptions of fact, on which the report is to be based,including a direction that the parties affected must endeavour to agree on the instructions to be provided to the expert witnesses.