What is the ruling when a terminally ill wife seeks Khul' by offering an amount exceeding her potential inheritance?

Primary text

If the wife seeks Khul' by offering an amount exceeding her potential inheritance, the excess portion is nullified. This is because the excess is suspected to be an attempt to transfer her wealth to him without proper consideration, in a manner not generally permissible as he is an heir, resembling a bequest or admission of debt, which is voidable. The portion equivalent to her inheritance is not viewed with suspicion.