It seems to me that there is another issue. IIRC, Rav Moshe says that Chalav Companies is like Chalav Yisrael. But if one decided to take on real Chalav Yisrael, then that practice becomes a neder (see Igros Moshe, it think it’s in Y”D 1 pages 82-89). Breaking a neder is a very serious matter.
As in all cases CYLOR.