If this is used as input to a randomness pool and filtered through a hash function, ideally together with mouse, keyboard and network event timing as in the lin

If this is used as input to a randomness pool and filtered through a hash function, ideally together with mouse, keyboard and network event timing as in the linux random device, this should be very hard to break, even with some biases. I would not have used the output of such a device directly, even if the output appeared random on statistical tests, just becuase the biases you mentioned. There will still usually be some randomness in the output, even when it is biased.