(a) A debtor or secondary obligor may waive the right to notification of disposition of collateral under section 28-9-611 only by an agreement to that effect entered into and authenticated after default.
(b) A debtor may waive the right to require disposition of collateral under section 28-9-620(e) only by an agreement to that effect entered into and authenticated after default.
(c) Except in a consumer goods transaction, a debtor or secondary obligor may waive the right to redeem collateral under section 28-9-623 only by an agreement to that effect entered into and authenticated after default.