The Rogan-Gladen step divides by TPR+TNR-1, so the uncertainty in TNR matters most, and a random 100-label sample at a ~90% pass rate leaves only about 10 truly bad outputs to estimate it from. It may be worth stratifying the labeling (oversample judge-Pass items, or known-bad ones) and bootstrapping a confidence interval on the corrected rate. Also, TPR/TNR are only valid for that judge model and prompt version, so any judge change would seem to need a fresh label check. Have you looked at how stable they are across prompt revisions?