Selected posts are those that today receive an upvote from @upex and @steem.botto The comments must match what is written in the post. And it should be a short comment
For those who do not wish to receive such comments, they should be given the opportunity to choose "turn off comments from AI"

The point is that these comments must be identifiable as AI-generated content in my opinion.

I completely agree, it should be stated in the comment that it is AI generated and with a small picture and text showing it.
Using a separate account like "xpilar-ai" can help identify AI-generated content, which is critical for transparency.

For example, authors who used a specific tag in their post will receive the comment.

That's a good idea