It would be nice if presented with a box to add a value that the return key added said value rather than clicking another key.
I'm sure there are other cases but the Type and Attribute manager, adding legal value list to constraints is the one I'm struggling with today.
You type in the value and have to click the + sign to add the value. There are no other real options tied to this text box. So you can only add. If you hit the enter key it will actually close the whole dialog leading you to have to go back in type in the value again and click the +.