This improves user experience by allowing users to fully use the numeric keypad when entering numbers and dates. At present this is a two handed affair or a full move across the keyboard when typing with the right hand and reaching across the keyboard to the tab key.
It also allows us to implement search entry fields which work the same way as in a web browser. i.e the user types in a search term and presses the enter key to initiate the search.
This would only work with text, date and time and numeric fields only where "Allow multiple values" is unchecked. It would be indicated by a "Use enter key as field exit" check box which would be off by default and checked to activate the feature.