The way they've been doing it is to divide the entrants into groups of 6 by expected finish time & starting each group 5 minutes apart to minimise overtaking, fastest groups first so a smallish race of say 250 people will be broken down into 42 micro-races. They could probably get the start groups down to about 2 minutes apart for shorter stuff like 5K.
I'd actually welcome that at the best of times. Would be like being 'promoted' or 'relegated' each time you moved group!