Yes, I agree. Leave them in until all are hatched. I have a sportman and I used to take them out as soon as they were dry. Big mistake! The chirping that the hatched chicks do encourage the other chicks to hatch.
Sometimes I have to help the chicks out of their shells. I don't like doing this, but at day 24 if I hear piping I help them out. If the humidity is too high, the inner lining becomes tough and jelly like. The chicks can't break through it and they drown. Incubation techniques vary to some degree with everyone I've ever talked to. It also varies from location to location.
Last year in Northern California, the weather was soooooo weird. Wet and cold, hot and muggy, then cold and dry and then hot and dry. All within a three month period. It really messed with my hatch rates. At one point I covered my incubator in a blanket just to stabilize the temp. I placed over 200 eggs and lost almost half. It was the most awful hatch year ever. I was always crying. The chicks would quit around day 15. Man, I pray it is good weather this year. I have 32 orders to fill. lol