(a) The arbitrators may require the parties before, during or following a hearing to submit arguments or briefs, in addition to any opening and closing briefs, on some or all of the issues in dispute.

(b) As a part of or in lieu of argument or briefs, the arbitrators, prior to taking the issues under submission for decision, may require the parties to submit proposed findings of fact and conclusions of law on some or all of the issues. When a proposed finding of fact is thus required to be submitted on an issue, the failure of a party to propose such finding may be treated by an arbitrator as a waiver of that party's contentions with respect thereto.