I can see the value of a thank button for IDs (in that someone who might otherwise want to click “Agree” would click “Thank” instead) but I’m not sure a Like button for a comment would be as beneficial. Remember, every like would have to be recorded somewhere, growing the iNat database quite a bit and possibly slowing things down. For sure it’s great being able to add a like to a comment, but would it be worth the extra burden?
Something like a yes/no vote if a comment is helpful, which could then be used to populate an ID page for a taxon, would probably be a better use of a button there. My two cents.