Those excessive property checks are pretty limited to basically the construction of object literals, and it does it because its normally an error if you have a

Those excessive property checks are pretty limited to basically the construction of object literals, and it does it because its normally an error if you have a very explict type but your literal expression doesn't match it. Typescript really does nothing to enforce anything around excess properties except for that narrow case. Branding doesn't really enforce anything except what the user asserts is the case. Its not the same thing.