Problem with assign ing 'global' action to multiple layers

The layer manager in Rhino 5 for Mac is deficient in this way. What we need is a complete rewrite of the layer manager to work cross-platform. This is a huge task that @dale is trying to get himself psyched up for…it’s a big task.

I know this is not the answer you are looking for, but there is nothing wrong with your particular copy of Rhino 5 for Mac; it is a general problem.