Source code of writing the struct byte by byte with a 'update' for each individual byte: https://github.com/arduino/ArduinoCore-avr/blob/master/libraries/EEPROM/src/EEPROM.h#L140
Source code of writing the struct byte by byte with a 'update' for each individual byte: https://github.com/arduino/ArduinoCore-avr/blob/master/libraries/EEPROM/src/EEPROM.h#L140