I'm not sure what you mean, deterministic hashing does not create more entropy than you started with. Lower-quality inputs means lower-quality results. You only want to use low-quality sources if the good stuff is too scarce or expensive.

Imagine that tomorrow some reaction caused all those lava-lamps to cloud over into pure, constant, and uniform milky white. What effect would that have? It would make the system at least somewhat less secure, no matter how many hash functions were already scattered around the place.