[jcranmer]

What I meant by "attack surface" here is probably a lot narrower than what you're used to. I'm using it to focus on the code size concern. I was trying to visualize it in terms of "how many opportunities do you have to try to break the system" (as surface area) versus "what can you actually do once you've made the first breach" (as volume), and didn't fully coherently rewrite the explanation to excise the surface area/volume distinction I originally made.