[JonahBraun]

I've done this and it works for normal typing. The downside is key combinations do not work across the keyboards (at least on Mac OS X). Example, pressing cmd on the left keyboard and p on the right keyboard will not trigger cmd-p.

[technomancy]

I'm pretty sure this problem is specific to Macs; other OSes allow modifiers from one keyboard to affect keys pressed on other devices.

[lowbloodsugar]

https://pqrs.org/osx/karabiner/document.html.en#implicit

"When you are using multiple keyboards, modifier keys are shared with all keyboards."

[hiattp]

Hmm that might be a configuration issue, my combinations work as expected. I'm in Vim pretty much the entire day so if key combinations didn't work this would be a non-starter

[WildUtah]

That might be a killer in EMCAS, but you can type in Vim all day without any chords except the shift key. I don't understand the reference in op as if Vim required tons of control keys like EMACS either.