When heading for the main North Sound entrance, our experience has been that once you pass Mountain Point you have two choices:
1 - Start the motor in order to turn more eastward and follow the coast of Mosquito Island, or...
2 - Keep on sailing, which involves going considerably farther north to line up a tack into the North Sound.

We're usually a bit impatient to get to our destination, and choose option 1. Even so, I resist the temptation to round Mosquito Rock closely. Doing so puts you right next to Colquhoun Reef for its entire length, where one unexpected problem (e.g. your engine dies) could quickly land you on the reef. So I continue some distance past Mosquito Rock before making a right turn toward the entrance markers.

By the way, our trips have mostly been in winter, when the wind tends to be a bit more northerly.

Dan cheers