Maybe this is just a silly idea and there's other priorities, but i'll throw it out there. Seeing how the only use for poppy flowers is in snuff, what if they added a new ceramic object like a flower vase or pot, and you could collect a bunch of poppy flowers and put them in? It would be a liftable oject that you could set wherever you wanted then, and serve absolutely no purpose other than to look snazzy. Maybe you could put in straw or inkweed or whatever to make different arrangements with different sprites?
If you REALLY wanted a purpose you could make it attract hypothetical "birds and bees" to boost crop gowth like beehives, but i don't think that's necessary. I like the idea of having a purely useless, purely aesthetic object in the game. (and i feel guilty throwing out poppy flowers)