As for the tech stuff, what I also don't understand is the collision avoidance. I got the 4 Pro also for having sensors on all 4 sides. I was not speeding, just few m/sec so they should have worked. I've seen YouTube videos where the P4P does a heck of a job avoiding stuff like trees, branches, etc.. and not only walls. Why did mine just flew into the tree without even hesitating? All question I don't find answers for at the moment. But anyhow, I will certainly fly with line in side in the future !!
Remember side sensors only work in beginner or tripod mode.