It all depends on the humidity of where you live (and/or in the incubation room). When I lived in Texas, I could easily do dry hatches. In fact, if anything- sometimes the humidity was too high.
Here in Colorado though, I would think dry hatching would be very difficult. I have never tried it because it is so hard as it is to keep the humidity in a decent range even with a large water surface area in the incubator.
With the rains here, the humidity has been ranging toward 70% on "dry" days and 90%+ during the actual rain storms, n my kitchen where I have the incubators.
I have a hygrometer measuring the ambient inside air in the kitchen telling me this. I've been shocked that I'm not getting thunder storms over the stove.
I brought some bantam chicken eggs in from outside yesterday and candled some of the more evenly sized ones to look for the air cell. Well, after I barely found the tiny air cell, I candled the rest I brought in that day and found the same thing. I think what I will do is allow the water to run out from the wells and check the air cells again.
When I hatched out Uno, I didn't realize my son had been continually opening the incubator during the hatch. I had all kinds of problems and Uno's sibling actually died. Uno's eyes were so bad I thought she was blind. Turns out they were just crusted shut. It took a week of saline cleanings to get them to clear. I am surprised she can see.
So dry hatching in Colorado would NOT be a good idea. If I lived in a place with very high humidity, it might work though.
our humidity here is soooo unpredictable last week it was humid as all get out and this week dry as a rock soo i have to have humidity in my incubator!!!!! but in the south i think you could do a dry hatch and be fine.......i also have a question could you have your water wells full and spritz them??? would that be too much