The other thing that gets metal to settle down is time. Old time machine builders used to age their castings for months or years before machining them, with a heat treat in the middle, and sometimes age them again after rough machining to let them settle down. Manufacturing was different then...
One of the amazing things for me as a new machinist was removing one face of a 1/4 x 2" cold rolled steel bar and then noticing the banana shape it had afterwards. It ruined the part, but I sure learned something!