Mass. Gen. Laws ch. 203E § 203
The court shall not over the objection of a party, entertain proceedings under section 201 involving a trust registered or having its principal place of administration in another state, unless: (1) all appropriate parties could not be bound by litigation in the courts of the state where the trust is registered or has its principal place of administration; or (2) the interests of justice otherwise would seriously be impaired. The court may condition a stay or dismissal of a proceeding under this section on the consent of a party to submit to the jurisdiction of the state in which the trust is registered or has its principal place of administration or the court may grant a continuance or enter any other appropriate order.
Mass. Gen. Laws ch. 203E, § 203