I've just upgraded from my Osmo Action 1 to the Osmo Action 3 - sadly my official DJI ND Filter set doesn't seem to be compatible with the new Action 3 camera.
Are there any plans for official filters - or do we have to wait for aftermarket ones?

Hi there. Thank you for reaching out. Yes, the DJI Osmo Action ND filters are not compatible with the DJI Action 3. Also, it seems that there is no ND filter set available at the moment on our store website, however, we will coordinate this with our team for attention. You may want to check the link below for you to see the available accessories for the DJI Action 3. Thank you for your understanding and support.

https://store.dji.com/be/category/osmo-action-3?from=store-nav