I'm using a genright stinger and had to notch it a little bit so the antirock wouldn't hit. If the BFH is right at the frame rails, I think you can get away without cutting anything.
But it's just steel, if you want something to fit, nothing a good cut off/grinding wheel can't do.
Looking at the instructions for the Antirock it looks like this won’t be an issue. It looks like I will need to install the mounts over the brackets for the BFH II and at the most cut off the outside surface as shown in the installation video.