(a) This section applies only to a county adopting an order under Section 5.0622.
(b) The commissioners court may not modify the provisions of this subchapter except the commissioners court may provide in the order that an executory contract to which the order applies may not be used to purchase land for residential purposes unless the conversion authorized by Section 5.081 is required to occur not later than three years after the date the executory contract is entered into.