This a late reply but I mainly use Autopilot “continue mission” on loss of radio signal with the rc. In this mode the mission is uploaded to the Mavic at the start and the mission is then executed by the Mavic. In this mode it does not matter how much processing power the host iPhone or ipad has. You can plan the mission to alter the gimbal pitch and it is executed by the Mavic when there is no radio link with the RC. I use this mode in preference to “return home on signal loss.” These Autopilot missions are executed by the host device iphone or iPad and require a lot of CPU power to run smoothly, and i have experience periodic app crashes (I use an iPhone 7 or iPad
Air 2) if the host device does not have enough grunt. My experience with Litchi is that when RC is lost the mission continues on the planned flight path but the speed drops and the gimbal pitch remains unchanged, it looks like Litchi manages the flight path by uploading into the Mavic at the start of the flight and the speed and gimbal pitch from the host device during the mission. This is not case with Autopilot “continue mission” mode.