Hi Jon,
Sure, a bunch of ones do. Kasefilter, Haida, Desmond/ice, and probably others. There are so many new brands.....You have to use an adapter, as the magnetic filters need a steel ring that they can stick to. So, for example, you put a Kase magnetic filter adapter on the lens. You can then use a magnetic lens cap. Take the cap off and simply set the filter in place. What that kind of system, there's no need to thread on filters in the field. For me, threading a filter is often not a problem, but sometimes it is, because the camera is in a difficult position, and it's especially important if I don't want the camera to move at all when I change filters.
Honestly, this was more important with my D600 and a R72 filter than with the Z9. With the D600, I had to take the IR filter off to compose and focus a photo. With the Z9, I don't have to, and so having magnetic filters isn't quite as important....but I already have a bunch of big (and expensive!) ones, and so I'd like to stick to that system.