(5) A local exchange telecommunications company that elects under paragraph (1), (2) or (3) may amend its network modernization plan to extend the period of time within which broadband service must be made available to a customer to up to ten business days after the customer's request for broadband service.
(6) A local exchange telecommunications company operating under an amended network modernization plan may subsequently petition the commission for approval of further modification of its amended network modernization plan, which the commission may grant upon good cause shown.