Ah, that's disappointing. Another reason to be glad I haven't upgraded yet, I guess.

Also, wow, I'm glad I don't maintain any popular open source projects on GitHub: https://github.com/tekezo/Karabiner/issues/660. I can't believe the number of people who think "+1", "me too", and "donated" messages are at all helpful.

Also, looks like Karabiner Elements exists as a rewrite for Sierra. https://github.com/tekezo/Karabiner-Elements Haven't yet checked if it supports the same dual behavior, though.

It's being worked on, but the latest macOS also adds Caps Lock to Escape mapping as a builtin preference.

I'm an Emacs user though, so I like it being Control as a modifier/Escape if pressed alone. Just having Caps Lock function as escape wouldn't help.