It is now possible to use Read&Write for Mac’s Screenmasking and Screenshot Reader feature across multiple screens.
To enable Screenmasking and Screenshot Reader across multiple screens:-
1 Go to System Settings
2 Click on Desktop & Dock
3 Untick “Displays have separate Spaces”
4 You will need to log out before changes can be applied. Once this is done, you’ll be able to use Screenmasking across multiple screen.