For STM32F030C8 is the MCU_ID suitable for a device ID, is it unique? The STM32F0xx products integrate an MCU ID code. This ID identifies the ST MCU part number and the die revision. Since there is no UNIQUE_ID for STM32F030.

[Tesla DeLorean]

It identifies a die revision, and will be on potentially millions of devices, perhaps with different packages or pin counts.

If you want something device unique, have your production line programming process write one into small area of flash.