(a) The owner of a property which is subject to preferential assessment or for which preferential assessment is sought, and the political subdivision in which said property is situated, shall have the right of appeal in accordance with existing law.

(a.1) In the event a change relating to composting in this act becomes effective during an active appeal and is applicable to the active appeal, no roll-back tax shall be due or collected and the roll-back tax shall be reimbursed if already paid for such activities to which roll-back taxes were applied.

(b) When roll-back taxes for prior years are to be collected as provided above, no person and no political subdivision shall be permitted to question any assessment of any prior year before the Board of Assessment Appeals unless a timely appeal was filed pursuant to the requirements of the acts of Assembly relating to assessment appeals during the time period for which appeals for that year would normally be taken.