Pangram has their FP rate and FN rate rates here:

https://www.pangram.com/research/model-card/pangram-4

> Pangram 4 achieves a 0.0041% false positive rate (roughly 1 in 24,000) on 1,000,000 human-written English FineWeb evaluation examples

> Overall False Negative Rate is 0.3396% on English AI generations (26 generator models)