In Firefox, I find myself duplicating tabs for various reasons, but it's only possible with the mouse. I like controlling Firefox functions with the keyboard, as it's more convenient for controlling from a remote keyboard than a mouse sometimes (Maybe I'm just weird). I would appreciate a keyboard shortcut for duplicating the current tab, staying on the first tab if possible ("When you open a link, image or media in a new tab, switch to it immediately" is unchecked, but it still switches to the new duplicate).