Hi Greg,
Desktop is a valid use case, with many desktop browsers now supporting pwa's being installed within the browser application instance.
You can quickly demonstrate and evaluate the limitations for yourself in Outsystems (service studio) as follows:
1. New Application
2. Start from an app
3. Select a mobile app (Task Manager is a good option)
4. Once installed, open the app and click on distribute tab
5. Click on toggle 'Distribute as PWA'
6. click on 'click here to open in the browser'. Make sure you are using a modern browser such as Chrone
7. In your Browser there will be an option to install the application i.e. Task Manager
8. This will then install the pwa into the browser i.e. Windows\Start Menu\Programs\Chrome Apps\Task Manager and will even show the app with the desired app icon that was used in Service Studio
Sam