Chicks don't drown - they suffocate because the air cell hasn't grown large enough to sustain them until they are able to make an external pip. This is where candling during incubation is particularly important.
I have hatched quail in 85% humidity no problem. I've even incubated with high humidity the whole of the incubation period and had 100% hatches. Eggs hatch out just fine in the rainforest. The key is temperature and ventilation. If your temperature is too low you will run into problems because not enough water evaporates off. Temperature is far more important in a small incubator than humidity. If you have condensation inside your incubator then the room it is in is too cold.
https://extension.psu.edu/science-of-incubation