Jeff uses the Chronivac to make his mother forcefully feminize him. The idea of being forced into being a girl gets Jeff hard, he strokes his cock as he makes changes.
First Jeff makes it so that once the feminization has begun, he will be unable to use the chronivac to back out of it. It doesn’t feel as erotic if he can just escape whenever he wants. Secondly, he makes it so that as his feminization progresses, his biological sex will shift in sync, until he is completely female. One week after becoming female, he will be able to access the chronivac again. Last, he makes it so that he forgets the changes he’s made, and forgets about the chronivac until he’s able to access it again, so he can live an authentic feminization.
He submits the changes to begin the next day, and undresses for bed.