I agree with you, Mrs. K. While feed restriction followed by return to good rations may induce reproduction, I can't see how it would be in the best interests of the animals, nor would it be beneficial to them in the long run.
An other reason to have an incubator, even if you do end up with a broody who cooperates with your plan: Any number of things can interfere with her successfully completing her hatch. She could be disturbed off the nest. She could be wiped out by a predator. She could quit before eggs hatch...
This has not been my experience. In my experience, a young cockrel raised with pullets is a terror to them. A more mature rooster will leave the pullets alone until they are POL, while a young cockrel will not. Yes, there is a bit of size difference, but a good rooster gets the job done...