Great analysis, but the argument at the end still seems wrong. The methodology has been carefully designed so that the clock jitter only adds random noise, not

Great analysis, but the argument at the end still seems wrong. The methodology has been carefully designed so that the clock jitter only adds random noise, not a directional bias. Even if the oscillator consistently runs fast by triggering 90 ppm early, it doesn't predictably increase the probability of a 0 or 1 bit. I suppose you could get more randomness using von Neumann's method for a biased coin - either waiting for multiple time periods, or with multiple decay sources in parallel. Or XOR the bits with a shitty but cheap source of randomness. But it's more valuable to be able to put an upper bound on your bias is - here, something like 10^-12 - and ensure that's acceptable for your application.