Hi,
I found this topic, because I have exactly this use case for a master slave combination of two ESP32. They are connected via RS485.
What I like to now is, did anybody realized this feature, and is willing to share his / her experiences?
Thank you very much
Andy

I used this tool https://github.com/chrisjoyce911/esp32FOTA with success in my application.
It works well with an esp32 for OTA-update of firmware as well as for a SPIFFS partition update.

espFOTA.cpp includes update.h
To start an update they use bool canBegin = Update.begin(contentLength); .

If ...