It would be nice to have control of PT speed
Why is 40 mph important?
40 mph is the approximate speed of your torpedoes after you drop them. If you set up a collision course (Constant Bearing Decreasing Range) with your target while traveling 40 mph and then drop your torpedoes they will hit the target (assuming it stays in a straight path).
My experience it is either shift w or else it throttles back to zero when you take your finger off the button. It would be nice if the throttle controlled the throttle. Did they have more than one forward gear? It seems counter intuitive to house a button to animate a throttle quadrant.