Shift+Enter = <br> rather than <p>

Isn't that what it does?

Yes I typed it backwards. Should be
Shift+Enter = '< p >' Enter = '< br >' But the point is fairly obvious. There needs to be a way to switch the default behavior of the enter key.

Is this a GUI editor thing?

Yeah its in the rich text editor, default behaviour for TinyMCE. I think I saw some changes around this recently but I'm not sure, I think it might now be dependent on the soft vs hard break setting?