We have used amp-list and amp-mustache successfully in several situations.

However, the requirement that the root term is "items":[{}] is limiting and basically requires full edit control of the target JSON file.
Example:

  {
    "items":
      [
        {

        }
      ]
  }

Here's our proposal:
Require the developer to specify the root term when reading a HTTPS/CORS/JSON document.
A developer already has to specify tree navigation with a series of open and close (# and /) statements.
Why not simply require the developer to specify the root term?

For example, if root is "items": [{}], then the opening statement is {{#items}}.
Then, if there are properties on a target page, one would target them as follows:
{{#items}}{{#Properties}}{{CID}}{{/Properties}}{{/items}}

Alternatively, if the root term is PropertyTable, then the statement would be as follows:
{{#PropertyTable}}{{#Properties}}{{CID}}{{/Properties}}{{/PropertyTable}}

Of course the JSON file with the root terms PropertyTable would have to be a valid array, as follows:

{
  "PropertyTable": {
    "Properties": [
      {
        "CID": 2244,
        "MolecularFormula": "C9H8O4"
      }
    ]
  }
}

Is there a systematic problem with this approach?