Sure. That is definitely the cause, I tried wrapping the errors in #if UNITY_EDITOR but that just caused more error. I suggest you just try to build for macOS and you should be able to find them all.
I won't be able to test it since I dont own a mac. All I can suggest is make a backup of your scene, then use the MAST tools button to remove MAST component script from the gameobjects placed with MAST. Then move MAST out of your project before the build.
You don't need a Mac to build for a Mac. The Windows version of Unity can build for any platform. But I think you should get build errors even if you build for Windows. Did you try that?
