Flashing unverified or incorrect firmware can "brick" your router, turning it into a useless electronic brick. It is vital to ensure that any new firmware is compatible with your specific hardware, and that it is in the correct language (often English) for your region. Using verified firmware provides:

These examples underscore: Verified is not a luxury; it is a firewall for your fiber line.

: Enhanced dual-band performance (2.4GHz and 5GHz) and better support for mesh networking through solutions like Maintenance and Verification

Unverified firmware often comes from different hardware revisions. The F670L has internal revisions (e.g., V1, V2, V3.0, V5.0). Flashing a V3.0 file onto a V5.0 board will overwrite the bootloader, leaving you with a device that only shows power lights.