Takeoff Mode Help

Hoping the Ardupilot Arduplane guru’s can offer some insight. I have TAKEOFF mode configured and working on my (various) aircraft; Arduplane v4.0.5. I have created a short video (with some slow motion) to review the characteristics of the aircraft on takeoff BEFORE I take over control with FBWA. Hoping some experts can review my setup and explain some the questions I have outlined in the video. For example, during the climb out the aircraft rolls hard left at a specific altitude and drops throttle for a moment, and quickly throttles up again. Please take a look and let me know your thoughts.

Video: Skyhunter Takeoff Mode

There is a topic related with this behavior:

Also it seems to be solved in the next release: