Ah, here you go:
ESP32S3:
FQBN: esp32:esp32:XIAO_ESP32S3
Using board ‘XIAO_ESP32S3’ from platform in folder: /Users/john_s/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0
Using core ‘esp32’ from platform in folder: /Users/john_s/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0
ESP32C6:
FQBN: esp32:esp32:XIAO_ESP32C6
Using board ‘XIAO_ESP32C6’ from platform in folder: /Users/john_s/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0
Using core ‘esp32’ from platform in folder: /Users/john_s/Library/Arduino15/packages/esp32/hardware/esp32/3.2.0