Immunity from other proceedings granted under the indirect tax settlement scheme; appeals disposed and matters become conclusive. Upon issuance of an order under subsection (4) of section 211 the appeal before the Commissioner (Appeals) stands disposed and the declarant receives immunity from all proceedings under the Act in respect of the declared indirect tax dispute; the declaration under section 211(1) becomes conclusive on that order and the impugned order may not be reopened in any proceeding under the Act.