A sketch plat of a major subdivision may be submitted for preliminary discussion before the preliminary plat is prepared. This step is recommended by the Planning Board. As its name indicates, the sketch plat is designed to enable the Planning Board and the applicant to discuss principles involved before the applicant has gone to the expense of completing detailed engineering drawings. The Planning Board shall act on such a plat and, if satisfactory, give the sketch plat approval. This approval will not be binding upon the developer, the Township, or the Township Planning Board, and will be subject to change, but will enable the applicant to proceed on a reasonably sound basis. It should be emphasized that sketch plat approval does not carry the authority to proceed with construction.