I'm using a Teensy 4.1 as a pass-through on a one-handed gaming keyboard to implement full single-handed typing and improve cursor navigation and access to It's working great and I'm getting used to it quickly, but unfortunately I'm also programming another Teensy that is connected to the same system. It's far too easy to select the wrong Teensy and end up re-programming the keyboard pass-through.

How can I put the Teensy into a 'quiet' mode where it only functions as a keyboard and the Teensyduino IDE doesn't see it?