Mizoram GST amendment allows manual filing, adds appellate authority with appeal timelines, and updates refund application forms. The Rules amend the Mizoram GST Rules, clarifying that exempt-supply aggregates exclude certain notified services; make supplier invoice issuance discretionary in the specified provision; introduce mirror manual filing and processing provisions treating electronic references as including manual submission in prescribed Forms; establish an Appellate Authority framework with appeals to Commissioner or Additional Commissioner depending on the rank of the order issuing officer and set limitation periods; permit termination of specified appointments by the Central Government with Council Chairperson approval; and insert detailed manual refund application and order forms with required declarations and calculation statements.