I haven’t done much more work on this, but it’s working pretty well for me.
I just took the path of least resistance and added the chords to my local plugins directory; my Kaleidoscope config is now on github, with the chord plugin in particular here.
It’s very much in the developer phase; the configuration is right in the plugin, and I’m not sure how exactly it should be set up (e.g., should combos persist across layers). So it’s certainly not ready for general use yet, but if you’re desperate, you might be able to get it working now, and the interest makes it marginally more likely that I’ll polish it up in the near future.