GPIO21/25 as outputs

The User Guide (22.3.4) AT+WIOW command states “the parameter is stored in EEPROM without using AT&W” does this mean every time you change the state of the output the current state is stored in EEPROM? (I’m thinking about the erase/write cycles)
I want to implement an occasional (slow) burst of serial data using GPIO21/25 as clk & data. How do I stop the EEPROM being written?
There’s an I2C port on the IESM so can I do something similar for the two inbuilt GPIOs?