I have the Polar Pro, You will have to re-balance the camera/filter with coins or weights.
A CP (Circular Polarizer) is used in bright sunny water or snow conditions. It will slow down the shutter and help reduce jello in the video. It can enhance the blues in sky and seeing through water and contrast based on how it is rotated when mounted on the lens. Direction of flight also relative to the sun also affects the effect of the Polarizer on the video. The ND (Neutral Density) filter also reduces the jello in videos and controls contrast. I believe it tones down colors that can be re-enhanced in post processing. I have found that these filters are wind catchers and can cause your gimbal to twitch when flying in high winds or when flying fast.
You will have to balance out on two spots, behind on the plate (lower right looking at the back) and on the front left of the arm/motor looking at the front of the camera. Each is different, you will have to play to get your gimbal to be able to balance when off perfectly center and up. I use the SRP and they are the best. Here is an example of the ND8: