My understanding, perhaps faulty is that the Freewell filters were designed with input/help/request...something....from DroneWorks, so they may have an exclusive with those for a bit.
I used a polarized filter own my
Evo 2 Pro today within issues. In fact, I have used a few of the filters from the Freewell kit with no issues. Even my Mavic Mini works fine with the Tiffen filters.
Despite what I am reading here, I always install filters with the aircraft turned off to avoid potential damage to the gimbal. IDK why some drone companies would suggest installing while the drone is powered on.