what does quake mode do?
Desktop equivalent is that you have a terminal available at a short-cut/button-press that will always show it but not fully hide the rest, no matter what other context you're in. Pretty handy.
I cant be the only person who uses Quake-style terminals at fullscreen. The second part of your sentence is the crucial bit: the ability to instantly conjure a persistent terminal regardless of whatever else I have on screen.
What I find annoying with my workflow (linux) is that starting a terminal and shell takes a lot of time. I wonder if it's possible to have a terminal always loaded so that my keybinding for creating a terminal would actually: move terminal in current workspace, focus it, then spawn another invisible terminal in the background.
So the idea would be that you start tmux somehow/somewhere, then in your new shell you can do `tmux attach` to get into that session from anywhere, and if you close this new shell, you can still do `tmux attach` to get back to where you were.
Use rxvt-unicode or another terminal that has a client/server mode. Start up a server in the background on boot or login (e.g. as a systemd user service), and make your keybind launch a new client process. Should be pretty much instant.
I am a single massive monitor kind of person. Quake-style terminal + all apps in maximized window + multiple desktops (with a shortcut to switch between them) is so good. Pull up the same terminal no matter which desktop you are on.