If the developer has followed the standards prescribed for final approval and has duly recorded the plat as required by this chapter the Planning Board may extend such period of protection for extensions of one year but not to exceed three extensions. Notwithstanding any other provisions of this chapter, the granting of final approval terminates the time period of preliminary approval for the section granted final approval.

In case of a subdivision for 150 acres or more, the Planning Board may grant the rights referred to in § 30-19.9 for such period of time, longer than two years, as shall be determined by the Planning Board to be reasonable, taking into consideration the number of dwelling units and nonresidential floor area permissible under final approval, economic conditions, and the comprehensiveness of the development. The developer may apply for thereafter and the Planning Board may thereafter grant an extension of final approval for such additional period of time as shall be determined by the Planning Board to be reasonable, taking into consideration the above factors.