No, and your rubric question is the sharp way to put it. A gate that emits only a number is an authority you can't audit or regression-test: when it disagrees with a human you can't tell whether it misread the rubric or the rubric itself is wrong, because the comparison that would show you got thrown away. The trace is also how you catch drift, since a prompt tweak can quietly move the judge's standard and you only see that if there's a trace to diff. The number is the output; the rubric comparison is the thing you actually version and trust.