I have posted this issue in another forum thread: my problem is that my autopilot does not turn even when it has passed the waypoint. The highlighted course line both on my 740 and also on my Android tablet does not switch to the next leg of the flight plan until I am many miles past the waypoint, so unless I turn off the autopilot and manually turn the aircraft, it just continues on the old heading. What gives? Is there a setting that I don't know about?
As to your specific question, what about a setting which will activate the next leg when you are some distance from the waypoint, like 1/2 mile? Then the autopilot would treat the new course as the desired track and the intercept function or whatever your autopilot uses would turn and intercept it. It seems unnecessarily complex to calculate standard rate turns etc.