The Secretary may, with respect to a contract entered into under this subchapter, make exceptions in the regulations promulgated to carry out this subchapter, or waive such regulations, if the Secretary finds that such exception or waiver is in the best interest of the Indians served by the contract or is consistent with the policies of this subchapter, and is not contrary to statutory law. In reviewing each request, the Secretary shall follow the timeline, findings, assistance, hearing, and appeal procedures set forth in section
450f of this title.