1.Do you have any sample code and tool for writing MAC ID in mass production .
2.Can you tell us the BLE MAC ID of the write address .
You can use PSoC4-BLE-SFLASH-Update.exe available as part of PSoC Programmer installation directory (C:\Program Files (x86)\Cypress\Programmer\Examples\Misc\PSoC4-BLE-SFLASH-Update\Executable folder).
Please refer to the steps in Setting Bluetooth Device Address – KBA211407
Use PSoC4-BLE-SFLASH-Update.exe corrupt hex image could be useful.