They report false negative rate (FNR) here:

https://www.pangram.com/research/model-card/pangram-3-3

  Academic Writing  FNR=0.00%  N=48443
  Creative Writing  FNR=0.23%  N=41940
  RAID              FNR=0.93%  N=66855

Yeah, that corresponds to a high value of my 1. The other three values are also important though.