Nice post! I recently did something similar.

Not an expert in NLP so I have this question: what if I want to associate named entities together? For example, if I trained “QUANTITY” and “PRODUCT”, and I have an utterance of “can I get 2 of PRODUCT_A and 3 of PRODUCT_B”, how do I somehow get a structured output where it associates 2 with A and 3 with B?