Ideally, you'd like them to lose between 12 and 16% of their starting weight by lockdown. If they don't lose enough, they die and if they lose too much they shrinkwrap and die too.
I didn't weigh my first batch, but I stuck to what must have been an ideal humidity as they all hatched. I'm sure yours will be fine too as long as you weren't running too low or too high for your area.
It's fun to weigh them as they incubate and see how they're doing. I was incubating 112 eggs (still got 8 left to hatch) in two incubators, so if some didn't lose enough, I'd move them all to the one incubator and set the humidity a bit lower so they'd catch up with the others. It kept me busy for 21 days, anyway!