Is it permissible to stipulate not upholding justice in certain matters (such as clothing, adornment, and lodging) when marrying a second wife, for the sake of ihsan (doing good), while upholding justice in other matters (such as household chores, inheritance, children's rights, food, and drink)?

Allah has permitted a Muslim man to marry up to four women, provided he deals justly with them in terms of lodging, food, drink, clothing, dwelling, and adornment. If a woman agrees to waive some of her rights, there is no sin upon the husband, but she has the right to retract her waiver whenever she wishes. It is not permissible for the husband to stipulate to a woman he intends to marry that he will not be just in these matters. Nor is it valid to waive the right to inheritance before death, because it is relinquishing a right before it becomes due.