Hi Tom,

If you will change layer visibility in Model (turn off or freeze layer), while you are in the "Model tab" as you call it, all changes will be immediately applied to all viewports in all Layouts. And this is true for all AutoCAD versions regardless platform - Mac or PC.

On the other hand you can freeze (hide) layers for individual Viewports in Layouts using VP Freeze property. And this will not affect Layers visibility in Model.

Layers states feature you showed in the screencast works independently for Model and Paper spaces, so if you change Layer State in Model (not inside viewport whole you are in the one of the Layout tabs), then changes will be visible in all viewports in all Layouts.