As I’ve mentioned before, WD is a relatively recent “discovered” requirement of 112(a) and hasn’t been endorsed by the Supreme Court.

And? It is relatively recently “discovered” because it was relatively recently codified. In O’Reilly v. Morse the Supreme Court articulated a very good and sensible limitation to what a patent can cover. In 1952 the Congress—recognizing the salutary nature of this common-law limitation—codified it in the first paragraph of §112. Now that the statutory text “written description” has become the focus by which Congress maintained this limitation in the warp and weave of U.S. patent law, that is the means by which this limitation must be (can be) enforced.

The common thing to do in the past was to trap the claims between the “point out and particularly claim” requirement of what is now 112(b) and the judicial exceptions to 101.

Great. That was the common thing to do before the 1952 Act retained certain features of the earlier common law of patents and excised other features. Now that the law has been codified, the old ways are relevant insofar as the codification carried them over, and irrelevant insofar as the codification excluded them. “Written description” in §112(a) is the text by which the Morse restriction was carried through the 1952 bottle neck, and therefore “written description” (and enablement) are the means by which this restriction should be applied (when relevant, or not applied where not relevant, according to the statutory text).

Consider the instant claimset – this was a pre-means-plus claim, but assume the argument was “The claim should be construed to cover the machinery described in the specification.” In that case, the claim fails under 112(b), because the language of the claim fails to point out and particularly claim the invention described in the spec.

I do not really disagree with your analysis of the claim set here, but I would suggest that it is not particularly helpful to transpose claims from an age when the U.S. had a “central claiming” regime, and then analyze them according to our modern, “peripheral claiming” laws. Indeed, at the time that this patent granted, there was not even a legal requirement for claims at all, so to speak of “claims” in this patent is problematically anachronistic.

Instead, the federal circuit created the WD test, which is inherently inferior to achieve the purposes explained here and in Morse.

Inferior or not, the CCPA “created” the WD test in recognition of the fact that the Congress codified a written description test for the CCPA to apply. I happen to think that WD is actually a better test than “abstract idea,” but better or worse is almost irrelevant. It is the Congress who is entrusted by our agreed-upon constitutional allocation of powers to set the standards. The Congress wrote “written description,” but did not write “abstract idea,” so there is adequate legal warrant to apply a “written description” test and not adequate legal warrant to apply an “abstract idea” test.

Using the WD test, it is insufficient to point out that the claim is not limited by means, and instead there has to be an analysis about whether the disclosed spec examples “fill the breadth” or “fill the scope” of the claimed genus.

Hm, if you say so. The test works fine in my end of the technology space. Seems to me that it would work fine in your end as well, if only people wanted to make it work. In other words, the problem is not with the test, but rather with the arbiters. Meanwhile, the new Iancu guidance shows that even your putatively preferable test can be bent out of all recognition if the arbiters want to do so. In other words, it looks to me less that the WD test is inherently inferior to the “abstract idea” test, and rather that the arbiters of compliance just want the rules of both tests to bend for one particular art field.