OK. Thank you very much! I've switched from screen to tmux and like it better. But the new package might help people who prefer screen.
You might want to add the following sentences to screen's package description: "Screen has keybindings which are similar to those of tmux. But screen is older and more widely available." That way people who've been experiencing bugs will know that there's an alternative with similar keybindings available -- i.e. tmux.