(a) Where an appointment does not satisfy the formal requirements specified in the creating instrument as provided in subdivision (a) of Section 630, the court may excuse compliance with the formal requirements and determine that exercise of the appointment was effective if both of the following requirements are satisfied:
(1) The appointment approximates the manner of appointment prescribed by the donor.
(2) The failure to satisfy the formal requirements does not defeat the accomplishment of a significant purpose of the donor.
(b) This section does not permit a court to excuse compliance with a specific reference requirement under Section 632.