Rule 1010. Dismissal or separate trial of third-party complaint. The court may dismiss a third-party complaint without prejudice, order a separate trial of the third-party claim or of any separate issue thereof, or make such other order as may be just. In exercising its discretion, the court shall consider whether the controversy between the third-party plaintiff and the third-party defendant will unduly delay the determination of the main action or prejudice the substantial rights of any party.