Where a tax district in a county, other than a complainant, desires to appear before the State Board to present oral argument or evidence in connection with a hearing to review a county equalization, it must serve a notice of such intention to appear upon the State Board or hearing officer within 30 days of receipt of notice of the proceeding as provided in section 8187-2.3 of this Subpart. Upon good cause, the requirement of this section in respect to the service of a notice of intention to appear may be waived.