For family court and the supporting agencies, there is a difference between inappropriate and actionable.
I called CPS twice in the months before our separation. Both times the ladies weren't concerned about Ex raging at me in my preschooler's presence. But both added, "Call us back if she rages at your son." Clearly the dividing line for my area was whether son was the focus of an attack versus him seeing me attacked by her.
If your son is the focus of verbal or physical attack, then reporting it is proper. Does he have a counselor? Counselors and therapists, among others, are mandated reporters. And regular counseling would be so helpful for him.
There you have two options, reporting and/or getting him an experienced counselor familiar with DV, you can choose both.
However, people with aggressively acting-out personality disorders typically resist improving their behaviors. Or if they behave for a while, they can easily — almost predictably — relapse into prior patterns. I think that's what's happening here. The family needs strong boundaries (and consequences) for proper behaviors. Whatever it takes.
Do you expect to remain married to her once your son is grown and is a man in control of his own life and future? If so, then why put that off? Am I wrong to think you are suffering too?