Yes.

Warning:  Manually changing the configuration file for your router can cause it to no longer function.   There are no warranties on this information!  Change at your own risk.

Removing the DHCP Option 60 pattern match for "IP-STB" can be done by manually exporting the router configuration to a text file {In the web UI under "Advanced" -> "Configuration File"}, editing that file with your favorite text editor (e.g. notepad), and changing the string "IP-STB" to something that will never successfully match (like "TEST").  You can then re-load the configuration from the modified text file.

Note:  Changing this causes the STB to no longer have any specific QoS Setting (Likely the entire purpose behind having the vendor match here in the first place,)

Example subsection of original configuration:  {Changed line is in BOLD}

(dhcps
        (enabled(1))
        (lease_time(86400))
        (pool
          (0
            (start_ip(192.168.1.2))
            (end_ip(192.168.1.254))
          )
          (1
            (vendor_id(IP-STB))
            (start_ip(192.168.1.100))
            (end_ip(192.168.1.150))
            (qos
              (enabled(1))
              (priority(5))
            )
            (is_fixed(1))
          )
        )



Example subsection of modified configuration:

(dhcps
        (enabled(1))
        (lease_time(86400))
        (pool
          (0
            (start_ip(192.168.1.2))
            (end_ip(192.168.1.254))
          )
          (1
            (vendor_id(TEST))
            (start_ip(192.168.1.100))
            (end_ip(192.168.1.150))
            (qos
              (enabled(1))
              (priority(5))
            )
            (is_fixed(1))
          )
        )

Change at your own risk!.   The author, and FIOSFAQ.COM bear no responsibility for malfunctioning routers or configurations.