Does prodigy.models.ner.EntityRecognizer constructor modify the underlying nlp model?

Oh I understand what you mean now, sorry! And yes, your analysis seem correct: in the current stable version, the EntityRecognizer constructor will add a sentencizer for sentence segmentation by default – but this is definitely unideal and it's actually something we've removed for the upcoming version (currently available as a nightly). It usually doesn't matter that much, because the nlp object in the annotation model is updated and later discarded anyways – but there are cases where the sentence segmentation can impact the model's predictions, because the entity recognizer isn't allowed to predict entities across sentence boundaries.