The use case is basically to have layouts with a master area on the left side for my right monitor, and the same layouts only 'reflected horizontally' (using Layout.Reflect) on my left monitor, so that the master areas are always in the center. A solution that has separate layout sets per screen should be more than enough for this.
I have a vague memory of finding such a module way back when, but I've went through the entirety of xmonad-contrib recently (looked at xmonad-extras as well) and didn't find a solution for this.
There are separate layouts per workspace, and having separate workspaces per screen, but I want to switch between screens on the fly and have consistent layouts as described above.
In case I'm not missing any module in contrib, could someone please point me in a good starting direction as to how to implement such a thing?
Any help is greatly appreciated!