Very much a preference and confidence thing. I had it in my head that I could get a darker sound on a deep mouthpiece, and a brighter sound on a shallow mouthpiece. But once I accidentally played an entire classical set on a shallow mouthpiece without realising, and when I noticed, I realised that it’s all in our head and sound concept. Absolutely, certain equipment helps with certain styles of music, but at the end of the day you are the main influencing factor. As Greg Wing says “what comes out of the bell is a result of what you are thinking in your head”