I don't think you necessarily need multiple log ins for this. The reason why you cannot view multiple screens is that Mx apps are one-page often-refreshing applications. However, with good UX, you should allow users to execute their process using logical navigation and layout, so ideally, you should not need multiple screens.
In the same browser, you can open multiple tabs to view different parts of your application using the same session.
Alternatively, if you have enabled Multiple sessions per user in your runtime configuration, you can log in multiple times with the same account, either in different browsers, or in private sessions in the same browser. This will consume multiple licenses for the same user.