Benji, have you tried creating a dedicated paragraph style and setting the option in there to show a border around it, then adjusting the border padding so that e.g. top, left and right padding use a value like 2pt, while the bottom padding is set to a negative value like -2pt?
If you then save this paragraph style as a default for future projects, you can then assign a key command to create a text item using your chosen paragraph style right away.