Different humidities seem to work for different ones of us. I normally try for humidity in the range of 65% to 70% for lockdown, but once they start to hatch, the humidity goes up, maybe somewhere arount 85%. I would not worry about 75%. Like Yinepu, I'm more worried about low humidity.
In addition to them not drying, too high a humidity during hatching can cause rough unhealed navels, so you can look for that and maybe try to adjust next time if it is a problem. But they will heal when they go into the brooder. There are many more things that can happen to them due to low humidity during hatching, and many of those can be fatal. I'd be happy with 75% during lockdown.
Since you are using a paper towel to get there, be careful it doesn't dry out. I put a couple of those straws with the accordian bends in them together and use a syringe to put water in the incubator through a vent hole so I don't have to open the incubator during lockdown.
Good luck!