Use it on both the EOS-M itself and the EF / EF-M Adapter -. In a Markins quick release clamp Dovetail profile fits well and it also clamps securely. Only the safety pin on the Markins terminal hooked for something. Battery / memory card remains accessible even when mounted plate. Also contributes to not very much.
As one small flaw I see that the fastening screw can be secured with the supplied Allen key and not tools ... with bail or at least with slot for coins.