BP is as optimized as we want it to be. Understand this: We are under no obligation whatsoever to make a game that runs everywhere. Sure, we'd like to reach an audience that is as big as it can be, but at the same time, our vision for BP (Which includes some rather spectacular graphics) has to take precedence in the absence of monetary concerns. The "Official FSO build + compatibility pack" version is the lowest-end version we can support. Hell, in the release thread, we're specifically warning people off who're using Intel hardware, because we know that those do not have the horsepower to provide a good experience.
You are in that same boat.
BP's art assets were made with current mid-range gaming PCs in mind. We have no desire to compromise our visual fidelity any further, and will not provide or support a low-end version of the mod. You can try to reduce the number of effects in use, you can disable all the additional forms of texturing we use (glow, specular, environment, normal) via the Launcher's graphics section, and you can use the ingame options to further reduce the maximum texture resolution used by the game, but that will make the game almost unplayably ugly.