I recommend responding to whatever specific problematic things he might say rather than issuing a general warning.
I am responding to quite specific problematic things he's saying. My comment is in response to AAs and is in reply to a reply to his comment. If I were to directly reply to him saying the same thing, my intentions would probably be misunderstood.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.