How does one talk about one's conversion then from Protestantism to the Catholic Faith without any reference to doctrine? How does one say "After much study, I was convinced the X-doctrine is in error and so I came to believe as the Church teaches." Would that then be seen as a polemic attack?
Indeed, once you mention another confession by name - and, especially once you testify as to what that confession teaches - then you are subject to a member of the confession objecting that your statement is false, incomplete, a strawman or whatever. It is better just to say what you believe now and why on a caucus thread.