Any local government or governing authority proposing to use an alternative methodology shall submit its proposal to the Commission along with a statement explaining how and why the alternative differs from the above methodology. The alternative methodology shall be submitted to the Commission for review not later than the time of the issue identification review pursuant to Section 13504. Within a reasonable period of closing the public hearing on the alternative methodology, the Commission shall determine whether the alternative methodology addresses the policy requirements of Chapter 3 of the California Coastal Act of 1976 and should therefore be approved for use pursuant to Public Resources Code Section 30501(a).