Yup, I like the idea of using `CMD_` for both. (I was briefly thinking that maybe it would make it more likely to get confused or make mistakes when specifying the parameters to `register()`, but on the other hand not having to think of two separate constant names seems sensible to me.)

@lkcampbell I think @peterflynn was suggesting *just* doing it for the ones you're changing anyway (not everything).

I've used dangoor/BracketsExtensionGrabber to download all extensions - it's basically just a node app that you run. But it's flaky for some reason that I've never been able to figure out - sometimes it doesn't download some extensions, sometimes it stops in the middle. If you have trouble getting it to work let us know. Once you've downloaded the extensions, you should be able to just grep for the command constants to see if anyone's using them.

FYI, I'm going to be out the rest of the week - if you update this and someone else would like to grab it (@TomMalbran?) feel free.