yes it will fit a wide strap but I think it will an unstable mounting platform

Hi Ciril-Weyermann I only have GoPro experience in this regard. But I also see it that you are compatible with the wrist strap with a DJI Osmo Action 4 mounting adapter, such as the DJI Osmo Action 3 Adhesive Base Kit. I don't know whether this kit works with Osmo 4.

It is. The connections of the brackets have been the same for years ;)

Unfortunately I could only find chest straps in the Galaxus range, alternative hand straps cannot be found. Sorry.