In vi, I have mapped 'jj' to escape to be able to switch to command mode without using the annoying escape key. Now I want to have the same for command line editing for which I use vi-mode. I already have found the following solution:
bindkey '^j' vi-cmd-mode
lets you change with control-j into command mode. Still searching for a solution without modifier-keys as 'jj' or something similar.