Is it necessary to extend the shingle starter course beyond the very edge of Vented Drip Edge?

It is neither necessary nor recommended to extend the shingle starter course beyond the edge of Vented Drip Edge.

It is neither necessary nor recommended because Vented Drip Edge already has a built-in drip edge. The starter course should begin approximately 1/2 inch away from the leading edge of the Vented Drip Edge (refer to the Installation Instructions). If the roofing contractor is considering aligning the starter course with the leading edge of Vented Drip Edge the contractor should be mindful of the shingle nail line and the deck underneath so as to ensure a solid surface for nailing.