"You implied there is a choice, but as I understand it, there is no choice under US law."

The reporting requirements are not federal law, but state law.

In some states mental health practitioners are not required to report pedophiles for a sexual orientation at all, in other states it depends on whether the mental health practitioner feels that their patient might be a threat - which, given how the law frequently treats child lovers as inherently threatening, means that there is considerable variation in what mental health practitioners might do and what they might feel required to do. Furthermore, even in states with no special requirements for reporting pedophiles to the police, mental health practitioners are allowed to report anyone who they think might be a danger to others to the police.

And therein lies the problem: it is not easy to tell beforehand whether a particular mental health practitioner can be trusted or not, and of course even if they feel no pressure to report us they will face no legal or professional repercussions if they do.