I would go lower... Have you researched a "dry" hatch?
35-40% day 1-18 is my preferred level, regardless of external humidity. The darker my eggs the lower I go... all the way down to 18%. Then raise to 60-65% for hatch sometime during day 18. I get fantastic hatches this way.
A few % one way or the other won't have serious impact the way temperature will. If you are using a built in hyro/thermometer... I highly suggest getting a secondary calibrated one... this is a NUMBER ONE factor in successful hatches.
Also, move the eggs to another location daily inside the bator since temp variances occur throughout, even in forced air bators. This will help to ensure even development of the embryos and keep hatch frame tighter. I also take out vent plugs VERY early (OK always), forgetting to remove them can make for less hatching. And doing so from the start means I don't have to mess with trying to adjust humidity level mid incubation.
My very favorite hatching resource...
https://www.hubbardbreeders.com/media/incubation_guideen__053407700_1525_26062017.pdf
And if you haven't yet found this thread then it's also one of the best resources...
https://www.backyardchickens.com/articles/hatching-eggs-101.64195/
Good luck and happy hatching!
