Surprisingly, the timing requirements for digital seem to be slightly lower than it was for analog, at least if I heard the engineer correctly on site. It was something like 1.5 microseconds in the old days, but can be like 10 microseconds now. I could be wrong there.

No, you are right. And it is because digital has a much wider 'lock' range than analog. Analog only works 'in the moment' whereas digital can take the history of the signal so far into account and so not lose lock. If it gets too extreme it will still happen though so cumulative problems will still show up only much later.