I think that you can unblock disabled settings by saving the BIOS to disk, then editing a copy of it using AMIBCP (if I understand right from the thread about that utility) and them updating the BIOS with the edited version (if you are comfortable doing that). I know version 3.13 is available online and works in Windows, but I haven't tried it yet myself, so hopefully someone will confirm it.
See my graphics card database at www.gpuzoo.com
Constantly being worked on. Feel free to message me with any corrections or details of cards you would like me to research and add.