In #10907 (comment) @jsnkuhn wrote:

FYI, the other property reset i've used every time with border-area is background-origin: border-box;. Considering resetting border-box as an initial background-origin value might be of use as well since im my experience most devs are not familiar with that property.

https://codepen.io/jsnkuhn/pen/eYwoGgr?editors=1100
https://codepen.io/jsnkuhn/pen/LYKXGPo
https://codepen.io/jsnkuhn/pen/WNqaeOV
https://codepen.io/jsnkuhn/pen/OJeoapM

There's two relevant questions

• should background-origin check background-clip to compute a smart default value
• in the background shorthand, when one box keyword is specified it's applied to both background-clip and background-origin (spec); but border-area is not a valid keyword for background-origin, so should we default it to border-area.

I think we should definitely fix the latter. Unsure about the former, though it would certainly be helpful to authors.