Even better, hyper key: https://brettterpstra.com/2017/06/15/a-hyper-key-with-karabi...

(Functions as ESC if pressed alone, otherwise acts as hyper key which is great to use for keyboard shortcuts)

As a VIM guy myself, this was huge. I never felt like I was missing out having done this.

I've only been using vim (well, neovim) for a few months, but I just assumed everyone mapped ESC to the caps lock key. Nearly every beginner tutorial recommended it, for good reason.