Good question lilJoe one I asked myself many times. So I experimented once and didn’t turn them even for incubator time. Disastrous results so the exercise to the yolk is important. I’m sure in the nest the eggs get rolled about more than we realize.I don't get it....
What do we have all these 'hatching rules' such as you MUST keep the pointy end down and when your storing them keep pointy and turn the eggs 2-3 times a day when storing?
The hens don't do this.
Most of the time when I have a problem incubating I think "What would a broody do?" and then all is good.