Wow. Hmm. 50% might just work for lockdown.I don't know if this will help or not, but, I can tell you what just happened to me last week.
I had eggs in my incubator, and never did switch them over to the hatcher. Meaning.... the humidity never was increased. It was around 35%. Five of the eight eggs hatched. Nice clean hatch, too.....
Now to figure out the turner issue.
... because I would rather spend that $150 on coops than incubators...