(a) Unless the court orders otherwise, during a proceeding for adoption in which an agency places the adoptee with the petitioner:
(1) The agency retains legal but not physical custody of the adoptee until the adoption decree becomes final; but
(2) The agency may delegate to the petitioner responsibility for the care and support of the adoptee.
(b) Before a decree of adoption becomes final, the agency may for cause petition the court to dismiss the adoption proceeding and to restore full legal and physical custody of the minor to the agency; and the court may grant the petition on finding that it is in the best interest of the minor.