a) When an application for either a special exception or a conditional use has been filed with either the Zoning Hearing Board or City Council, as relevant, and the subject matter of such application would ultimately constitute either a land development as defined in Section 107 of the Municipalities Planning Code or a subdivision as defined in Section 107 of the Pennsylvania Municipalities Planning Code, no change or amendment of the zoning, subdivision or other governing ordinance or plans shall affect the decision on such application adversely to the applicant and the applicant shall be entitled to a decision in accordance with the provisions of the governing ordinances or plans as they stood at the time the application was duly filed, provided, further, should such an application be approved by either the Zoning Hearing Board or City Council, as relevant, applicant shall be entitled to proceed with the submission of either land development or subdivision plans within a period of six (6) months or longer as may be approved by either the Zoning Hearing Board or City Council following the date of such approval in accordance with the provisions of the governing ordinances or plans as they stood at the time the application was duly filed before either the Zoning Hearing Board or City Council, as relevant. If either a Land Development or Subdivision Plan is so filed within said period, such plan shall be subject to the provisions of Section 508(1) through (4) of the Pennsylvania Municipalities Planning Code, and specifically to the time limitations of Section 508(4) of the Pennsylvania Municipalities Planning Code which shall commence as of the date of filing such Land Development or Subdivision Plan.