The intent of RCW 11.96A.260 through 11.96A.320 is to provide for the efficient settlement of disputes in trust, estate, and nonprobate matters through mediation and arbitration by providing any party the right to proceed first with mediation and then arbitration before formal judicial procedures may be utilized. Accordingly, any of the requirements or rights under RCW 11.96A.260 through 11.96A.320 are subject to any contrary agreement between the parties or the parties’ virtual representatives.