You can write the addresses to user flash. Every time you power on the device, you can retrive the addresses from user flash and add them to the whitelist again.
Do you have any example for writing/reading SFlash ?
When using bonding after pairing (set "Bonding requeriment: Bonding" in BLE component), whitelist is fill automatically. Then we can do CyBle_StoreBondingData function to write whitelist in RAM to the flash. When power fault reset, whitelist and bondlist will be updated from flash automatically.
If I had known those, I had solved some hours coding manually write/read operations in flash.
I hope this information keep somebody beginning not spending time.