https://www.4kshooters.net/2019/07/24/aurora-aperture-has-a-revolutionary-drop-in-filter-system-for-mirrorless-cameras/
i have their variable nd filter, it is quite good.
wish they had more options as i am a fuji user, maybe in a few monthes.
the only downside i had is that some filters are on back orders sometimes, small company