Jeffrey: I've left a private comment that we should probably decline this as a detail the CSS WG does not need to check with us on. I also filed a bug (https://github.com/w3c/csswg-drafts/issues/13510) that I read its spec and didn't see something I was looking for, but that wasn't a TAG comment. But I want to check all that with Xiaocheng. Anyone else have opinions? ...

Xiaochengh: Minor comment regarding the explainer - they don't have an alternatives considered section. They have a filter extension section that is a mix of alternatives and the actual filter extentions. The proposal looks fine overall except a concern about implementation complexity. With revert, we need to maintain every rule from each origin, and then each layer. We can't drop anything.

Jeffrey: That sounds like a good thing to flag.

Xiaochengh: It does sound like someone has implemented it, though, so I'm not sure how they did it.

Jeffrey: They have, but they haven't filed any positions yet.

Xiaochengh: It's already in the CSS 5, but those editors may add things before they are implementable.

Brian: These are from whether its implementable or not.

Jeffrey: It's from the Chrome team, but the other engines may have different architectures.

Dan: The other engines have file positions, just haven't shared with us.

Jeffrey: So it may not be worth us asking again.

Xiaochengh: If others are not concerned, then we can resolve and say it's good. Will send that comment.

Brian: You can say that broadly speaking it seems ok, but of course browser architectures will vary. So, subject to reality, there may be other constraints that make this more difficult/costly to do in some engines than others.

Jeffrey: And your comment that they're missing alternatives is worth keeping.