I can't tell someone else how to run the incubators or hatchers, but we cannot get anything to hatch with the humidity that high. We run our incubator at about 30-35% humidity and hatch at about 60%. We have to run our incubators and hatchers on lower humidity to get our eggs to evaporate correctly. We drown too many chicks if we try to run a higher humidity. Hopefully, someone else will chime in later. I know that there are other breeders in this group who are very successful at hatching Marans chicks.
Just My Experiences,
Ernie Haire