(1) Nothing in [these rules] requires rating organizations or their participating insurers to immediately refile rates in effect. Any participating insurer of a rating organization may continue to use all rates and deviations in effect until such rates are disapproved or until the insurer makes its own filing to change its rates, either by making an independent filing or by filing a reference filing adoption form adopting the rating organization's prospective loss costs, or the insurer's modification of them.