Store & retrieve parameters after sketch update
There is no need for an SD card.
You can write all relevant parameters into a file in SPIFFS (e.g. json if you like) before starting the OTA update. During initialization you read the file and set the parameters accordingly.
SPIFFS does not get erased when doing an update (at least that's true for the OTA library that I'm using). If it does get erased in your case, there probably is an option in the OTA lib to disable flash erase, just like there is the same option when uploading a sketch via serial.