That's more keystrokes. ;)
nmap gz :term zsh<CR>
Same number of keystrokes, and does not override any existing normal-mode command from what I can see. :nnoremap <C-z> :term<Return>
works for me (tmux in urxvt).Ctrl-Z only gets converted to SIGTSTP if the terminal has ISIG set. For example, try `stty -isig; sleep 5` and try to suspend or interrupt the sleep command.