You can map it so that tapping caps lock is escape and holding it down is control.

Then you have to set a timeout, which introduces lag in your typing.

Only for the escape key. I don't find that there's any noticeable lag in practice.

It can be both. I know people who have it configured to be escape when it's pressed and released, but control when it's held down in combination with another key.

How do you do that? I normally use the keyboard preferences to change the capslock on my MBP to control. I'd like escape there too, but I'd like to avoid running additional software to enable it.

I use Karabiner and it's truly a wonderful piece of software. I'm super sensitive to any lag or missent keys, but this actually works very well and I don't even think about it anymore.

Here's the modification I use: https://pqrs.org/osx/karabiner/complex_modifications/#caps_l...

"Change caps_lock to control if pressed with other keys, to escape if pressed alone."

I'm not sure. I think on linux/X11 it's just xmodmap wizardry, any maybe on macos you need third party software, but don't take my word for it. It's not something I've really investigated since I'm personally satisfied with capslock=escape.