(it might be that I miss something ?but )
setting
_SnapToMeshObject
to a Mesh (and maybe hide the mesh or its layer afterwards)
gives a quite special snapping-behaviour.
As far as I see there is no Status / Feedback in the UI that shows that _SnapToMeshObject is active - same for similar commands.
I think it would be nice to have some feeback in the Osnap panel or the Status-Bar about those special modi. (similar to project)
thanks - kind regards - tom