I regretted upgrading to Sierra because I lost my favorite functionality of Karabiner. But I got most of the features back when I started using Hammerspoon. I

I regretted upgrading to Sierra because I lost my favorite functionality of Karabiner. But I got most of the features back when I started using Hammerspoon. It's not GUI friendly, but it's doable and there's a lot of scripts available. It's similar to Window's Autohotkey which I use at work, but Hammerspoon has a sane, real language (Lua). My other suggestion is to actually replace keyboard. ErgoDox EZ and Ultimate Hacking Keyboard have almost all the features I need from Karabiner, but is saved to the firmware, so I can take the keyboard anywhere and it just works. Also, they're mechanical keyboard, so it's nice to type on.