Hello, I am working on a project using the teensy 4.0 and I only need Serial and Audio but under the USB Type list their is not an option with just Serial and Audio. If I want to use Serial and Audio I also have to include MIDI.
Also sort of as he mentioned, it may also depend on what you are needing Serial for. If you want something like a debug Serial port, the Audio USB version also includes a RAW HID used for Serial emulation. Not sure if that gives you what you need/want.