How do you plan to raise the humidity for lockdown? Have you tested your planned method to do that yet?
Don't overstress on the humidity percentage yet. Pete55's idea of weighing them to determine moisture loss is pretty good, but you need to weight enough to get an average. Don't just weight one and call that good for all of them. You need a really good scale for that and it is easier to get an accurate weight if you weigh a bunch together. Some people look at the growth of the air sac to see if the humidity is about right.
Different humidities work for different ones of us. If you weigh them, you can adjust as you go along. If you don't weigh them or check air sac growth, I suggest you pick a humidity and try to be fairly consistent throughout the hatch. When it is over analyze the eggs that did not hatch to try to determine if you need to adjust the humidity.
Good luck!