(...) But even if I’m oversimplifying, I do think that my simple numbers demonstrate that the higher the sample rate, the more critical timing will become.
Curious that I would expect the opposite if trying to simplify - for the same jitter, as you are using more samples at an higher sample rate for a transition, and jitter is random and centered around a fixed time, I would expect some kind of cancellation due to later filtering. But may be I am wrong!