Ask the user why he's not answering anymore when evidence of his theft has come out, I have all Telegram screenshots.
Then share those telegram screenshots in the appropriate board.
Should I waste time in reporting him after having been scammed maybe?
If you provide the evidence that shows he indeed scammed you, chances are that he ends up getting tagged and flagged which might save someone else from losing money. So no, I don't think that would be waste of your time.
Ask the few users who left positive reviews to show THEIR proofs, why are you asking for proofs just to people saying they've been scammed? This forum is full of scammers, you know this very well but it looks like you're not interested in stopping them. Oh, you say "chances are that he ends up getting tagged and flagged which might save someone else from losing money": tagged and flagged?? In any serious forum a scammer is banned, not flagged!