I like your thinking, and it will take all my will, but yes, you are right. Question is,, if my case goes to fact find, do I mention at that point, rather than CAFCAS?This is a head f**k. I still struggle to find a way of justifying the gentle approach to myself. Here is the best I can manage.
They would have to entirely reject the other side if they were to give weight to reports such as the above. It is not necessary to convince Cafcass that your ex is the problem. You only need give reason for them to believe you are not the problem. It is probably not a good idea to force a choice between two evils - i.e. drunken, abusive, layabout father; manipulative, alienating, maniacal mother. Realistically, they will likely come down in favour of your ex if forced to choose. The child is well enough, the child is with her. Status quo is all important.
If you are reasonable to a fault, you contradict what Cafcass are being asked to believe of you. If you present witness accounts to show your ex is the problem, you ask Cafcass to condemn your ex. I believe an attack from the weaker party works against them.