Having an option on the screen or in the button parameters to prevent the user from double clicking on any element twice or others when the server is processing.

Per example if the server is slow the action logic may still be processing and some users have the tendency to double click buttons (like Create/Save) repeatedly, duplicating records (per example).

You can avoid this by using the Button Loading widget on Mobile and Reactive Apps, but there is no option for the whole screen. On Traditional Web you have to implement your own logic or use a Forge Component (Page Loader) or (Button Locker), per example.