As long as it's not too distracting, I guess. But the game's very quiet in terms of ambience, so I would think this a good area to expand. There's always the slider bar to scale it back if needed.
Checking just now, the game files aren't too large (70mb), so it doesn't seem like there'd be a problem with adding more samples.
In fact, I think it would actually be pretty cool if users could customize something like that themselves. I only seem to recall one Android game ever that let the user modify the graphics & sounds, and that was <strong>Xenowar</strong>, a cool X-COM-style game.
The game I mentioned in the OP actually comes as a mobile game. Link [<strong>here</strong>]
In fact, most crafting systems across all platforms work similarly to the way I described. It's the most common variety AFAIK. If you check any of them out, I think you'll find that in practice, it's not really inconvenient to manually add ingredients and that sort of thing. It's ordinary and expected IME.
Obviously I don't know the limitations you're working with, though. Maybe such a thing is indeed impossible given your dev tools.