Yes, you can use the gimbal/camera normally with the filters on.
What they are trying to say in their weird Mandarin-to-English translation is, put the filter on straight and evenly, and make sure it's pushed down all the way onto the camera lens. Don't try to put it on at an angle. It's not that difficult. I usually push mine all the way down and then give them a few twists to make sure they're on snug and seated all the way.