The major concern to me, is that there isn't really any guidance from the FBI on what you can and can't do, which may lead to some big issues.

https://www.ic3.gov/Media/Y2024/PSA240329 https://www.justice.gov/criminal/criminal-ceos/citizens-guide-us-federal-law-child-pornography

They've actually issued warnings and guidance, and the law itself is pretty concise regarding what's allowed.

(8) "child pornography" means any visual depiction, including any photograph, film, video, picture, or computer or computer-generated image or picture, whether made or produced by electronic, mechanical, or other means, of sexually explicit conduct, where-

(A) the production of such visual depiction involves the use of a minor engaging in sexually explicit conduct;

(B) such visual depiction is a digital image, computer image, or computer-generated image that is, or is indistinguishable from, that of a minor engaging in sexually explicit conduct; or

(C) such visual depiction has been created, adapted, or modified to appear that an identifiable minor is engaging in sexually explicit conduct.

...

(11) the term "indistinguishable" used with respect to a depiction, means virtually indistinguishable, in that the depiction is such that an ordinary person viewing the depiction would conclude that the depiction is of an actual minor engaged in sexually explicit conduct. This definition does not apply to depictions that are drawings, cartoons, sculptures, or paintings depicting minors or adults.

https://uscode.house.gov/view.xhtml?hl=false&edition=prelim&req=granuleid%3AUSC-prelim-title18-section2256&f=treesort&num=0

If you're going to be doing grey area things you should do more than the five minutes of searching I did to find those honestly.

It was basically born out of a supreme Court case in the early 2000s regarding an earlier version of the law that went much further and banned anything that "appeared to be" or "was presented as" sexual content involving minors, regardless of context, and could have plausibly been used against young looking adult models, artistically significant paintings, or things like Romeo and Juliet, which are neither explicit nor vulgar but could be presented as involving child sexual activity. (Juliet's 14 and it's clearly labeled as a love story).
After the relevant provisions were struck down, a new law was passed that factored in the justices rationale and commentary about what would be acceptable and gave us our current system of "it has to have some redeeming value, or not involve actual children and plausibly not look like it involves actual children".