Does the Redmi Note 14 Pro+ 5G support a Bootloader lock?

Yes, the Redmi Note 14 Pro+ 5G supports a Bootloader lock.
For your reference, here is more information about a Bootloader lock:
1. Bootloader Lock is a security feature on Android devices that prevents unauthorized modifications to the device's system partition. The bootloader is a low-level program that runs before the operating system starts, and it is responsible for initializing the hardware and loading the operating system;
2. When the bootloader is locked, the device prevents any attempt to flash (install) custom firmware or operating systems. This is particularly useful for preventing unauthorized software modifications that could compromise security, performance, or user data;
3. A locked bootloader acts as a barrier against attackers who can try to exploit vulnerabilities in the bootloader to gain control of the device. It also prevents the installation of unofficial or unverified recovery images, which could be used to root the device or install custom ROMs.