not to leave you hanging there; this is what I found in my .zshrc to enable the functionality.
autoload edit-command-line
zle -N edit-command-line
bindkey -M vicmd v edit-command-line
... could've sworn that was included more default-y
Re:Use vi editor in shell
by worldofprasanna on Tuesday November 22, 2016 @11:57PM
(#13020168)
Hey thanks yoo1l. It worked like charm ...
PS: Blog updated !!! https://worldofprasanna.github.io/using-vi-in-zsh
https://dougblack.io/words/zsh-vi-mode.html
Above link explains the usage, but I couldn t use it for some reason even after setting EDITOR variable.