For those who have question, I have your answers & a video showing everything in action.
Video: https://youtu.be/RQV0h5ECmFM
• USB-C port has 5.1k ohm resistors, which allow me to use the C to C cables, and not just C to A cables. (Meaning I can even use PD chargers).
• Button allows me to pair, and disconnect BT devices. (The module itself remembers last connect device and tries to reconnect automatically - 1 click disconnects - holding pairs new speaker in range).
• Switch can turn on/off Bluetooth. Turning it off allows sound to go back to device speakers.
• LED is off by default, but when BT device is connected to 3DS, it lights up so ik when it’s currently connected to something.
• The audio jack on the console itself still functions as normal. I can continue to use wired devices if needed.