You are free to call yourself a professional. You can’t get others to call you a professional. Fact is when a good workman claims to be
“a professional “ it often sours the client on hiring him. I’ve heard people comment about the title , they thought it strange ,or even funny. There are formal ways of addressing Kings , Presidents, Potentates ,but sometimes they are not used even after the lucky
peasants are told how to behave when they meet the great people.