A written agreement among persons who are then members, including a sole member, or who have signed subscription or contribution agreements, relating to the control of any phase of the business and affairs of the cooperative, its liquidation, dissolution and termination, or the relations among members or persons who have signed subscription or contribution agreements is valid as provided in subsection 2. Other than the authorization of nonpatron membership interests as provided in section 501A.901 and nonpatron voting rights as provided in section 501A.810, whenever this chapter provides that a particular result may or must be obtained through a provision in a cooperative’s articles or bylaws, the same result can be accomplished through a member control agreement valid under this section or through a procedure established by a member control agreement valid under this section. However, the member control agreement must be authorized by the cooperative’s articles or bylaws and cannot conflict with the cooperative’s articles or bylaws. Any result accomplished through a membership control agreement under this section must be properly disclosed as provided in section 501A.901.

 Other than patron member voting control under section 501A.810 and patron member allocation and distribution provisions under sections 501A.1005 and 501A.1006, a written agreement among persons described in subsection 1 that relates to the control of or the liquidation, dissolution, and termination of the cooperative, the relations among them, or any phase of the business and affairs of the cooperative is valid if it meets the requirements of this subsection. This includes but is not limited to the management of its business, the declaration and payment of distributions, the sharing of profits and losses, the election of directors, the employment of members by the cooperative, or the arbitration of disputes. The written agreement must be signed by all persons who are then the members of the cooperative, whether or not the members all have voting power, and all those who have signed contribution agreements, regardless of whether those signatories will, when members, have voting power.

 This section does not apply to, limit, or restrict agreements otherwise valid, nor is the procedure set forth in this section the exclusive method of agreement among members or between the members and the cooperative with respect to any of the matters described.