ESPHome repairs encrypted firmware uploads for devices that cannot start normally and have entered safe mode. When the update key comes from the device’s configured Home Assistant connection key, a repair upload could fail on RP2040 devices or crash other chips.
J. Nick Koston makes the configured key available without starting the normal device connection. Keys supplied later through that connection can also be recovered from saved settings, although a storage limitation on ESP8266 and RP2040 can still prevent those devices from offering encryption in safe mode.