Question regarding model adaptation

I'm trying to add improve recognition of the specific phrases (I'm using vosk as recognizer for "smart speaker"). I followed the guide - https://alphacephei.com/vosk/adaptation , generated new `Gr.fst` and it works, and resulting model recognizes only phrases I added. But what if I want to update phrases model can recognize, and not replace it? Is it possible to find phrases which were used to generate original `Gr.fst`?