This seems to have been broken for me unless I add DEBIAN_PREVENT_KEYBOARD_CHANGES=yes to my .zshenv. I'm not sure if it was an update to ZSH, oh-my-zsh, or Ubuntu that causes the issue.
It's actually a plugin bundled with oh-my-zsh, but I copy-pasted the default keybindings from the github page you linked, and it's indeed pretty awesome.
To use it, I use: