Fair enough. I now see the connection (i.e. separate from DFU process another doc excludes DFU designated port from participating in your process.) Regardless the documentation is 100% correct re which port is DFU port. If your process fails, it could be for any number of reasons only one of which has to do with using the DFU port, so it is not a logical implication to conclude the failure means DFU port is wrong.