Applicants for preliminary approval shall be encouraged to submit for review by the Planning Board sketch site plans for informal discussions and recommendations. Said sketch site plans shall be used as a basis for changes and redesign and to avoid undue expense and delay in preparing more detailed plans and specifications. The Planning Board shall not be governed by any statutory time limits in its review of sketch site plans, and it is expressly understood that compliance with the Planning Board recommendations shall not bind the Planning Board in subsequent deliberations.