Request: It would be useful to be able to set up panes that scroll off the screen.
The scrolling capability is already there (it appears when the window size is reduced, so the cumulative width of the panes is less than the width of the reduced window).
What’s not there AFAICT is the ability to have panes whose cumulative width is more than a full (non-reduced-width) window.
Alternatively (though less usefully), let us narrow panes to just a tiny (unreadable) width.
The common use case is to have several panes open at once, with the currently focused pane being wide enough to work in, even in a window that is too narrow to hold all panes readably at the same time.