Standard key mappings are performed by the OS of the computer to which your keyboard is connected (either physically or via bluetooth or some such). When you pr

Standard key mappings are performed by the OS of the computer to which your keyboard is connected (either physically or via bluetooth or some such). When you press caps lock, the OS sees a caps lock keypress, but any application programs on your computer, including terminal, will see only an ESC keypress. Terminal will dutifully send the ESC press to the ssh program running in Terminal, which in turn should send it along to the remote host into which you are ssh'd.