I was a night owl last night and worked ZD9W on 40m at 01:00 local time.  As I was about to hit the sack, John called and said that he and Lanny had worked him back to back after I shut down.  Then about 13:40 today local, got him on 10m at 28.084 running the real F/H.   

As Lanny said, ZD9W is definitely working WXTJx F/H and not some other fork of the program.  However, when they are operating on the main watering holes for normal FT8, WSJTx won't allow F/H.  So if you are seeing compound, multiple streams on the main frequencies, he could be running MSHV or something similar that does not have F/H capabilities.  

73's