Disable the overlays
If you only want to use for example the Dispatcher, Achievements, Leaderboard and hide the visible overlays in-game, it’s totally possible.
Open main window at startup and Open game info overlay at startup must be disabled.
Then, Enable traffic reports notifications, Enable audio on traffic reports and notifications and Enable traffic report when enter an area also need to be disabled.
There you go, all the visual overlays in-game are disabled and you can only use the Dispatcher, Achievements and Leaderboards.