@gordon, I tried your command for 'Thunar' file manager (but should not matter right?) and the result is not what I wanted/expected.
- After running the command and logging back in, thunar window pops-up (each time I login, just like UM Welcome app does, unless disabled).
- Desktop icons are gone and right-click menu also gone.
- Opening file manager from menu (I am currently using advanced-mate-menu), does open thunar. However,
- Opening download folder from firefox still opens caja and not thunar.