(1) If —
(a) a compromise is proposed in proceedings to which rule 21.4 applies;
(b) some of the persons who are interested in, or who may be affected by the compromise are not parties to the proceedings;
(c) those persons are represented by a representative appointed under rule 21.4 when the court considers the proposed compromise; and
(d) the court is satisfied that the compromise will be for the benefit of those absent persons,
the court may approve the compromise.
(2) The persons for whose benefit the court may approve a compromise may be unborn or unascertained.
(3) The court's order approving the compromise binds those absent persons unless it has been set aside by the court.