Justoverclock that looks nice!
The question is indeed how to use that value as an actual feature. I assume a user would be aware they are writing a negative title/text, the question is what do you want to suggest or require when that happens.
If you're publishing reviews/feedback, there will obviously be both good and bad content. But using this to show an indicator next to a post or discussion might not work because a false positive would make the user appear to give the opposite review they actually intended 😅
The sentiment score could be used in something like Recaptcha's invisible v3, where each post gets assigned a score (not visible to regular users), and the admin can choose which score value goes to approval or review by moderators.