Tex. Business & Commerce Code § 9.602

Except as otherwise provided in Section 9.624, to the extent that they give rights to a debtor or obligor and impose duties on a secured party, the debtor or obligor may not waive or vary the rules stated in the following listed sections:

(1) Section 9.207(b)(4)(C), which deals with use and operation of the collateral by the secured party;

(2) Section 9.210, which deals with requests for an accounting and requests concerning a list of collateral and statement of account;

(3) Section 9.607(c), which deals with collection and enforcement of collateral;

(4) Sections 9.608(a) and 9.615(c) to the extent that they deal with application or payment of noncash proceeds of collection, enforcement, or disposition;

(5) Sections 9.608(a) and 9.615(d) to the extent that they require accounting for or payment of surplus proceeds of collateral;

(6) Section 9.609 to the extent that it imposes upon a secured party that takes possession of collateral without judicial process the duty to do so without breach of the peace;

(7) Sections 9.610(b), 9.611, 9.613, and 9.614, which deal with disposition of collateral;

(8) Section 9.615(f), which deals with calculation of a deficiency or surplus when a disposition is made to the secured party, a person related to the secured party, or a secondary obligor;

(9) Section 9.616, which deals with explanation of the calculation of a surplus or deficiency;

(10) Sections 9.620, 9.621, and 9.622, which deal with acceptance of collateral in satisfaction of obligation;

(11) Section 9.623, which deals with redemption of collateral;

(12) Section 9.624, which deals with permissible waivers; and

(13) Sections 9.625 and 9.626, which deal with the secured party's liability for failure to comply with this chapter.