When I use a plane as a shadow-catcher it becomes transparent but is still visible in reflections. Many people suggest unticking Glossy in the Ray Visibility section of the plane's Object properties. But this results in the shadows that the plane is catching also becoming invisible in reflections.
But this isn't what I want - the shadow catcher is transparent but the shadows it catches are not and I want the same whether looking at it directly or seeing it in reflections.
Any suggestions are much appreciated. And any explanation as to why this default behavior makes sense would also be interesting - it seems strange that something is handled differently depending on whether viewed directly or reflected.
The following renders show the issue clearly.
.blend file and the
.hdr can be found here: