I agree, it's very frustrating. It effectively makes the impacted P3s useless for serious video.
It seems however that most people who don't suffer from the issue are convinced we are not doing correct IMU and gimbal calibrations (cold or otherwise), are not trying mid air calibrating, or that we must have a hardware problem. They also think we can simply use the gimbal roll adjustment and our problems will be solved. Those of us who do suffer with the issue know we have done everything and that it's not hardware.
Regardless, unless DJI considers this a priority to fix we will probably never be able to record the beautiful video that we see so often on the forum. That is without considerable post processing as you noted.