I would say it increases the surface area that _must be attacked_ rather than the surface area available for a single attack. So like, if you have a square they just have to attack the square but if you have a cube they have to attack six squares. And really the attack vector of primary concern, i...

Skip a bunch of chapters and jump straight to Building a nostr:npub17tyke9lkgxd98ruyeul6wt3pj3s9uxzgp9hxu5tsenjmweue6sqq4y3mgl

Most are referring to a multi-vendor, multi-sig setup. If one vendor is a bad actor you still have the others protecting your ₿.