Can you exclude/not build the Facebook SDK with specific Unity build platforms?

I have a Unity project I'm working on for Android, iOS and Windows Metro. The Unity-Facebook SDK works great for Android and iOS but they haven't added support for Windows Metro yet. That's fine, I don't need Facebook for the Windows Metro app. However, because of the scripts from the Facebook SDK, I get tons of compile errors when I try to build a Windows Metro app.

I would ideally like to somehow exclude the Facebook SDK during my build for Windows Metro, but not for my other builds. This is so that I can maintain 1 code base for all projects (kinda what Unity is great for). I realize that I could edit EVERY facebook script and put in #if !UNITY_METRO_WHATEVER #endif around everything but I don't feel like I should have to do this.

Does anybody know how to not build the Facebook SDK with specific Unity platform builds?

Using the latest Unity and FB SDK 4.3.6 on Windows 8.1.