How does your setup work with a second monitor that comes and goes?
Use case: I have a laptop that I take everywhere for me, but I plug into a second monitor while at work. I also use multiple desktops, and this pattern is sometimes causing windows to jump to another desktop when disconnecting the monitor.
I had the same issue using unity/gnome on a laptop with 1-3 monitors. After I switched to i3 I was forced to set the monitor config manually with xrandr. I set up keyboard shortcuts for switching between 1-3 monitors. This fixed all the issues with automatic window placement since the window manager no longer tries to do this in an automatic fashion.
Tiling window managers definitely have a learning curve, but after I spent a weekend switching to one, I can't see myself ever wanting to go back to floating windows.
I have two bash scripts that set things appropriately -- laptop.sh and desktop.sh. Xrandr, xinput, xset things. There's probably a better way to handle this but it's not inconvenient enough to make me figure it out (or duckduckgo it).
My setup isn't the exact same as his but I've never had any problems plugging in a projector on my XMonad laptop. In the XMonad schema windows are always associated with one of the 9 workspaces and each screen displays one workspace with the windows all scaled to fit nicely in the display. When you unplug a screen the windows on the associated workspace stay on that workspace and don't go anywhere else.
Use case: I have a laptop that I take everywhere for me, but I plug into a second monitor while at work. I also use multiple desktops, and this pattern is sometimes causing windows to jump to another desktop when disconnecting the monitor.