I don't see why you would need such a complex system (spatial model) to switch between your apps. In my opinion, this has been solved perfectly many years ago. I simply use Super+ to launch/switch to my 10 most important applications. Supported out-of-the box by both Windows and Gnome and 100% predictable. Every shortcut invocation will launch exactly the right application.
(i3-gaps user) Tiling is basically an extension of this, and it can absolutely make your life easier if your work or play revolves around switching between workspaces that contain ~3+ windows each.