The more the better. Looks like you can get in three turns. While they will uneven in the number of hours: 10-4-10, the next day the opposite side would have the longer times therefore even out in the long run. Honestly I don't see how a broody can complete turn an egg; my impression of a broody chicken hen is that she is fussing at the eggs trying to rearrange things but honestly I can't see how she can get all the eggs turned. This is from observing a hen on a make shift pit of a nest packed full of eggs. Eggs three layers down hatched-- just don't see how it could get major turning like the top eggs could. IMO i think just budging the eggs has an mpact on the embryo as if to say, I'm here, I'm keeping you warm, and I'll fuss over you. My impression is that she does a great job of keeping the temp fairly steady. I have read some studies on the hatch rate of WHEN the eggs are turned, beginning, middle and end, The more the eggs are turned the better, and eggs do need turning thruout for the best results. Even a hen is fussing right thru hatching ( lockdown).
So if you have a day when only two turns are possible, in the end it won't really matter, especially if you are using a fored air type and the temp is even all around the egg. IMO still air ( top of egg closest to heating element) needs careful and regular turning.
I don't have a turner. ANd don't plan to. Sorry for the long winded lecture.