
The only way I can manage this is by clicking into each section, usually. I have found that you can “reload” an already interpreted line from the the upper half by pressing enter, and then using ctrl+a, backspace to delete the line in the staging area below, essentially moving into the bottom half without clicking. But this is very ugly, and I hate reaching for the mouse if I don’t have to.
For me Ctrl-Tab seems to do that.