Hi folks. @vierfuffzig has posted an issue for developers to track the TAKEOFF Mode vs Auto Takeofff behavior:
Regarding the turn on launch, this is actually a long standing problem. It comes from not relying on heading-lock instead of GPS ground/heading track due to it not being reliable yet and thus relying on gyro and compass which take a nasty G-shock and current/magnetic spike at full-throttle on takeoff. I have a pull-request that I posted a few months ago to address this (for auto takeoff) by using a virtual waypoint far away that it tracks towards during the climb.