it depends on how hard the boost hits, which mounts you have, the whole setup. I've seen a couple crack and I've seen most stay together.

Ask yourself though. Is the weight difference worth the potentially weaker subframe?

What I would automatically suggest if you plan on doing the frame is to get the aluminum oil pan and it's pickup tube. That pan makes changing the mount or pan gaskets super easy. And it's structural so you won't ever dent it.