unless I've missed something (entirely possible), nothing in either 336, or the existing FAA Interim Interpretation requires membership in a CBO. The texts require that operations be conducted within the scope of safety rules, and "programming" of a CBO.
Is that incorrect?
As I've discovered my homeowners' specifically states that operation of model airplanes *ARE* covered under personal liability (recently changed companies/underwriters), and my coverages are quite satisfactory, continuing membership seems redundant at this point, as the property owner / landlord only requires financial liability proof of coverage, and the AMA insurance has ALWAYS been "secondary" anyway....