Post #8 seems to be somewhat inaccurate as well as a little vague.
As a matter of curiosity, what metrics were used to determine its reliability and what statistical conclusions did you reach? What specific reliability issues did you encounter or observe that led you to conclude that information was stored "but not reliably as near as I could tell"? Do you have a code example to demonstrate this?
The R4 has two programmable chips - the ESP32 WiFi module and the Renesas R4AM1. The R4AM1 does have native EEPROM memory. The limitations of EEPROM in general and as applied to some Atmel chips have been known for a long time. Usually the amount of EEPROM available is very small and there have been concerns expressed regarding its longevity. However, I have a project that was published some 5 years ago that makes use of EEPROM memory to store settings and to date haven't received any significant complaint about problems in that area. That is not to say that problems might not occur, but at the same time I am not convinced that they are as pervasive or as frequent as is sometimes implied or that has been indicated by the AI bot used to generate/supplement the information in that post . It should also be borne in mind that the target audience for Arduino is education/hobbyist rather than professional or industrial deployment. I am not yet aware of what the word is on the longevity of EEPROM memory in the Renesas R4AM1? Its a completely different beast to the older Atmel 8-bit chips.
On the other hand, as correctly stated, Espressif did not implement EEPROM on their ESP32 series modules, a fact that can be determined by consulting the ESP32 datasheet. I presume this is the chip being referred to as Arduino R4 WiFi thereby conflating the UNO R4 board as a whole with the onboard ESP32 module. For compatibility reasons and convenience, the Arduino framework does implement an emulation of EEPROM using flash memory as a "workaround" which for that reason might not be particularly efficient, however the programmer is not tied to using that approach. The LittleFS filesystem can be used instead and configuration parameters or data stored in a file.