The initial time periods for filing a final report and for making distribution to each legatee and heir are extended for 90 days on a consent for extension of the time periods signed by the personal representative and each interested person and filed within 10 months from the date of appointment. Except as provided in subsection (c) of this section, a register of wills or a court may not extend the time periods established under this subtitle. If the time periods for filing a final report and making distribution to each legatee and heir have been extended under subsection (a) of this section, the register of wills may extend the time periods for an additional period not to exceed 90 days on the filing of a request for an additional extension of the time periods. A request filed under paragraph (1) of this subsection shall be: Signed by the personal representative and consented to by each interested person; and Delivered to the register of wills before the date for filing a final report as extended under subsection (a) of this section.