It actually gets even more confusing. Desktop mode (what you get when Steam is in desktop mode or you're tabbed out of big picture/TV mode) is completely separa

It actually gets even more confusing. Desktop mode (what you get when Steam is in desktop mode or you're tabbed out of big picture/TV mode) is completely separate from lizard mode (what you get when Steam isn't running or can't grab the desktop due to UAC/Secure Desktop). That matters because desktop mode still has customizable keybindings as usual, while lizard mode is completely hard-coded. Lizard mode also (obviously) doesn't support the soft keyboard, which would otherwise have been pretty useful from the lock/login screen.