That’s awesome, great work!
With the false negative rate being sufficiently low, if it passes without noticing any mistakes, then at least it’s probably not a disaster of a sentence. But even better is that with the false positives being this low, I basically know that if it notices a potential mistake on something, I should really think long and hard about where I messed up on xD. So it’s really ideal for making improvements with confidence, and having some guarantee that what you put in there is pretty decent Japanese, even if it could still be made slightly more natural. I’m gonna get a lot of use out of this