Red October doesn't use external decoders by design.
It could be added to a whitelist, but that would only allow it to be used in Custom mode and you would still need to instruct MC to use this decoder for the cineform codec.
Its not a bug, its a feature to protect every MC user from the crazyness of their own system and the broken DirectShow filters in this world.
Personally I think you slightly over-represent its popularity.
The codec may be good to send around high-quality demo material, but for actual playback, its just MUCH too slow. So even if MC could open these files, whats the big point.