Modifying Property Division And Separation Agreement

This is how modification is stated in my agreement:

MODIFICATION: This Agreement can be altered, amended or modified by
further written agreement duly executed by the parties. Any failure by either party to
specifically perform or to enforce performance exactly according to the letter of this Agreement
shall not constitute an alteration of the same by way of enlargement, reduction, estoppel or
otherwise, unless confirmed in writing by the parties. It is understood that the parties may by
mutual agreement make temporary modifications from time to time as conditions require and
that this Agreement shall nonetheless be binding upon the parties as written, except in the event
of a material breach.

My agreement also states:
NON-RECORDATION OF AGREEMENT: This Agreement shall not be recorded without the prior, express written consent of both parties. A Memorandum hereof, however, shall be executed by either party upon request of the other party and may be recorded in any recording office at any time. No such Memorandum of Agreement shall contain the details or financial provisions of this Agreement, except as otherwise specifically agreed to by the parties.

So, the agreement is not part of a court order.
The agreement is signed and notarized by both parties.
My question is- Do these modifications need to be notarized to be duly executed and binding, or can something be simply written down and signed by the parties?

It’s always better to have any agreements notarized, so as to avoid any later issues that may arise if one of you decides to challenge it. The notarization helps in court to show that the other party really did sign the agreement, etc.

Thank you for the response. I understand that notarization helps in court. I am wondering if a modification that is signed but not notarized and subsequently challenged in court will be upheld by the judge or if it will be considered invalid because it was not notarized. Is this up to the judge or does the judge have to follow a rule of law concerning this?

Yes, you would each need to sign and notarize it, making it a binding contract that should hold up in court. Best of luck to you!