As we all know the P3 gimbal was prone to sliding off it's pivot axis, ruining the camera cable and potentially other things in a minor crash. These gimbals are only held in place with a magnetic attraction, hence you can slide them off with a little pull, but you never want to do that because it ruins the camera cable. KillerRC and others made a Gimbal protector for the P3 to alleviate the problem, an aluminum milled replacement back cover to the gimbal that includes a retainer arm to prevent the gimbal from separating in the minor crash. It appears the P4 will need one of these also, assuming DJI didn't do anything internally to prevent the gimbal from easily separating. I don't see any retaining arm that prevents separation. I'm wondering why DJI didn't address that issue, which seems to be a simple fix.