Yeah, I'm not certain that this is a real issue. It might be? Certainly, I'm read in to things like TECL desync. I get the concern, that any disagreement in parsing policies is problematic for HTTP because of middleboxes. But I think the ship may have sailed on 0ah, and that it may be the case that you simply have to build HTTP systems to be bare-0ah-tolerant if you want your system to be resilient.
But what's bare-0ah-tolerant? Accepting _or_ ignoring bare 0ah's means you need to ensure all your moving parts agree, or you end up in the "one bit thinks this is two headers, others think it's one header".
The only situation where you don't need to know two policies match is when one of the policies rejects one of the combinations outright. Probably. Maybe.
EDIT: maybe it's better phrased as "all parts need to be bare-0ah-strict". But then it's fine if it's bare-0ah-reject; they just need to all be strict, one way or the other.