‘background-origin’ sounds very useful to me.
Also the gradients and multiple backgrounds would be great to have.
I don’t know if this is the place to coin new stuff that isn’t in the draft (or maybe it’s there, I probably missed it? Didn’t read the whole thing to be honest), but wouldn’t it be great to say something like:
li { background-rotate: 180%; }
Or…
li { background-flip: horizontal }
In my designs I’ve used rotated and mirrored images more than once, but of course had to use several images to get it done.
It would be a great bandwidth-saver. You just need one image and you can flip it around any way you like it.