Do you think that the technique of using the last 4 bits to choose a further pseudorandom 31 bits from the rest of the hash MIGHT mitigate SOME future weakness as a PRNG? Or do you have confidence it is completely useless? Or neither, of course.
I think it's weird. Either you trust your output to be pseudorandom or you don't. These weird hacks may be fine, but they feel like adding "safety" duct tape onto the wings of a passenger jet.
