It's weird that the only way to get the following structure:

  {
    "hosts": {
      "example.org": "localhost:8000",
      "foo.com": "localhost:9000",
      "sub.example.com": "localhost:9002"
    },
    "certfile": "path/to/cert.pem",
    "keyfile":"path/to/key.pem"
  }

is to write the following toml:

  certfile = "path/to/cert.pem"
  keyfile = "path/to/key.pem"

  [hosts]
  "example.org" = "localhost:8000"
  "foo.com" = "localhost:9000"
  "sub.example.com" = "localhost:9002"

and other toml orderings, like in the parent comment, fail.