Short answer: No.
The CAPM-6000 uses a BCM6848 chipset with proprietary VOIP drivers. There is no stable OpenWrt build. Flashing a generic Broadcom image will brick the VOIP phone port and the TR-069 management, causing LG U+ to charge you a ₩50,000 replacement fee. lg u wifi capm6000 firmware work
Before troubleshooting, verify the firmware you are running. Short answer: No
A: Unlikely. Slow speeds are usually signal-to-noise ratio (SNR) issues. Check the modem’s admin page under "Cable Stats." High upstream power (>52 dBmV) indicates a line problem, not firmware. 000 replacement fee. Before troubleshooting
Because LG U+ controls updates, you cannot manually download a firmware file from a public website (unlike Netgear or Asus). Here is how to force a firmware check/reinstall.