CTH,
I also encourage you to update the 740 to the latest software version. The latest issue of version 11.x.x has indeed "added improved auto-pilot turn anticipation" according to the update notes. I didn't know that the iFly software even did this until this last upgrade. I do know that my AP has turn anticipation in its software.
I use the auto-pilot similarly to you - I turn on the autopilot when cranking up and ensure that it is receiving the flight plan NEMA code from the 740, but I do not engage the servos until established on a rough heading in the correct direction after takeoff. I'm usually busy with comms with the local controller and switching to TRACON fairly soon after takeoff anyway. My autopilot is a Trio instead of the TruTrack but would not suspect that is the issue. When I engage the AP servos the AP begins intercepting the the flight path track to the first waypoint, joins it smoothly and begins following the flight plan.
I would try the updated iFly software first, then look at AP tracking and intercept options after that if it needs more refinement.
Best,
John