If you flash an incorrect bootloader image, the Nokia 3.4 can become a hard brick (no power, no LED, not recognized by PC). Recovery from hard brick requires an and authorized Qualcomm programmer – nearly impossible for normal users.
Do not buy a Nokia 3.4 expecting to unlock the bootloader. If you already own one, you cannot root or flash custom ROMs. Consider a device from Xiaomi (with unlock permission), Motorola, Google Pixel, or OnePlus for development.
