The saddle stays on 24/7 until they go broody and begin to sit, and then I remove it one morning when she comes out to eat and drink (her only outing of the day once she begins to sit tight) because by then the stag has calmed down and doesn't tread the hen turkey. At over twice the weight of a hen, the stags arent violent but just clumsy and heavy and can rip the skin off the back with one mating if there is no saddle...never worth taking that risk for the hen's sake.
This may be different with other breeds, but ours lay and sit better if they lay and hatch in separate houses, or at least a good distance apart, and screened off. Our friend had two tea cases side by side in a big shed, and the hens would get confused, steal each others eggs, and squabble...which didnt make for a good hatching from either. Ours laid about 18 or so eggs, and then began to sit. They were wonderful mothers, looked after the large hatch, and only squashed one....dont know how they manage not to with such big legs and feet!
Maybe we have just been lucky, but they are less precarious as parents than geese, or hens. good luck.