Thanks for the info, setting tabBarController.sidebar.preferredPlacement = .sidebar doesn't work in the setup above where the tab's viewController provider is a splitViewController. I guess it's better to stick to setting the tab's viewController to a navController and customizing it's viewController. I expect it will get easier to make these kind of customizations in later versions of the OS.

Just a quick follow if possible: What’s the cleanest way to keep that hidden first line non-editable?