Any performance incentive plan for officers and employees of the Materials Innovation and Recycling Authority that authorizes payments in addition to established salaries shall be in writing, apply to all officers and employees of the authority, provide for any such payment to be made on the basis of both the job performance of the officer or employee and the overall financial performance of the authority, and be subject to the approval of the board of directors of the authority pursuant to § 22a-261. No payments under such plan shall be made during any year that annual salary increases have been suspended. The provisions of this section shall not (1) limit the rights of any officer or employee under an existing collective bargaining agreement or (2) prohibit the payment of extra or overtime pay for extra or overtime work in accordance with written procedures adopted pursuant to § 22a-268a.