No amount of technology will be able to stop all people from being exposed to all forms of content at all times which may one day trigger PTSD symptoms. Social media shitholes use blacklists when they "should be" crowdsource-whitelisting content and not moderating anything at all. And then users decide for themselves if they wish to turn off the whitelist content filter and expose themselves to the content that may one day trigger PTSD symptoms.

Prepare your child for the path, not the path for your child.