As others have said, better off having everything out in the open from the get go.
Just curious, what waiver are you speaking of?
Never be discouraged from disclosing anything about your home. Buyers are unique and there may always be that one buyer that will accept a home with faults and all, because they just absolutely love the home.
So just disclose everything up front and im sure you will sleep better at night too!
Licensed Realtor in NJ and GA