It's not perhaps the solution that would suit everyone, but I'd bet
some users will prefer that to the way they are currently displayed.
A third option would indeed be a kind of pop-up buffer. And there
are probably other options.
Popup buffer and popup frame (perhaps a child frame?) are IMO the only
viable alternatives that are worth having in Emacs.
A popup frame is not an option for terminal users. A popup buffer
could be an option, but if I had to choose between the two, I think I
would choose the mode-line one, which is IMO less disturbing.
And here is (a first draft of) the code for a popup buffer.