Here is the answer I received from the race organizer about staging:
"Hi Theia, we will publish official race distance/age groups/ start waves in April, but here’s a general rule we follow;
Q: How are waves determined / created?
A: There is no seeding within age category waves.
the 100 miler will have one start wave
the 62 mile has two waves; 1st =Men open, 2nd= Masters, Women, SS, tandem ( subject to change based on numbers)
the 36 and 22 mile waves are created looking at previous years average times by age group. Fastest groups go off in earlier waves. Wave age categories are combined using avg. speed and category size. We try to keep waves around 125
62 waves go off at 10 AM followed by all 36 mile age group waves 10:08 - 10:30 and 22 mile age waves 10:32 - 10:44"