When you get to the Add Application prompt to browse for the app to be excluded, enter this: C:\Windows\explorer.exe Shell:AppsFolder

This will take you to the Applications folder where you can select "Settings" to be excluded.

Unfortunately, Settings is not really an application, but part of the operating system. It is referred to as the windows.immersivecontrolpanel located at "C:\Windows\ImmersiveControlPanel\SystemSettings.exe" but invoked by the OS using ms-settings commands.

I thought that trick might work, but I guess not.

Maybe someone else will have experience with how to block Settings from WindowBlinds.

Excluding ApplicationFrameHost.exe did the trick, thanks. I had tried excluding SystemSettings.exe but that wasn't enough.