I don't think I have the skill to learn a stenographer's keyboard, but I would love to have a small chorded keyboard just for macros.

I always liked the look of Doug Engelbart's one in the Mother of All Demos. It's very basic, but I'd be quite satisfied with something like that today. He demonstrates it at about 1:40:

https://www.youtube.com/watch?v=B6rKUf9DWRI

There are a bunch of macropads with open source firmware so you just need to find one you like and program in the macro/chording you want.