I don't know where you read about not crowing in front of you but it isn't true, there is no evidence what so ever of roosters crowing in front of anyone is a bad thing (or even means anything. There is an old superstition about crowing in front of you being very bad luck, and that a person "shouldn't let a rooster crow on your doorstep" which would bring bad luck for the rest of your life and even death - so whether what you read came from that I don't know but I know enough about cockerels to know that isn't true.
I promise you I have no wish to offend anyone who may read this but one of my biggest hates is when humans provoke an attack then blame the rooster or label him aggressive or unsafe, it also gets at me how so many blame a rooster for doing what they are designed and programmed to do and accuse the rooster of being aggressive when all they are doing is their job. It is my belief that cockerels deserve respect and understanding and is the owners responsibility to learn, gain and understand everything about roosters and about keeping a rooster. I also believe that learning their rooster is a great help to ensure they don't provoke an attack. I have great admiration for you due to you doing what needs to be done to prevent any provoked attacks i.e. no longer taking carrier bags near him.
I am asking you please to watch this video and take note of everything this guy is saying, he is an expert who is renowned for his expertise and skill in breeding, keeping and training roosters. In this video he uses Gamefowl only because he had an aggressive bird but all this is across the board for all cockerels - I believe this video may answer some if not all your questions and concerns.