Keep a close eye on them. Since he only has the one hen,, he is likely to overbreed her. If that happens, it will not be good for your girl.Thanks everyone for your replies! I haven't been able to find any local groups or forums for Japanese quail owners so this has been very helpful.
I agree that it's a bad idea to put the Tuxedo back in with my pharoah females. He seems pretty happy at the moment in his new setup, and the pharoah girls have relaxed a lot more in the adjacent cage. I added the Italian female to the Tuxedo's cage because they get along well. He's stopped crowing and sure enough they've been happily romancing.
I guess I need to decide whether to keep the Tuxedo or sell him- I had originally intended to have 1 male and four females. But he's happy with the Italian female, and my two pharoah females are happy with my other little rooster, who has a great temperament.