Still, we can't be sure that it has 100% accuracy and for the fact no detector can promise 100% accuracy because LLM uses what humans wrote in the past, so it is possible for someone to write something that can be flagged for AI.

Even though spam is against the forum rules, still it's not enforced strictly unless the user create spams too often.

But what can be done is to add something that show us what's the percentage of AI text present in every post using what you suggested can be helpful and it can be next to merit button or anywhere that looks good.