It is the sense of Congress that the States should develop an interstate compact for the collection of sales tax by remote sellers that identifies a clearly defined minimum substantial nexus between the remote seller and the taxing State, that simplifies registration, collection, remittance, auditing, and other compliance processes to the greatest extent possible in order to avoid undue burdens on interstate commerce, and that, due to such simplification, eliminates the need for the continuation of the small business remote seller exemption under section 4.