Content controls inside text boxes not supported in Word Online

ASK: support manipulation of content controls inside text boxes across all platforms, including Word Online.

We have scenarios where Text Boxes are used to position Content Controls outside of the normal text flow, both in the document header/footer and in the body.

But we are unable to perform actions on these Content Controls when running on Word Online because Content Controls within Text Boxes are not part of the returned items array when I run the following:

await Word.run(async (context) => {
    let contentControls = context.document.contentControls;

    contentControls.load();

    await context.sync();

    for (let i = 0; i < contentControls.items.length; i++) {
        let cc = contentControls.items[i];
        // cc will never be the Content Control within the Text Box <- Problem!!
    }

    await context.sync();
});

This works fine on Word 2016 on Windows.

We would need a way to load and manipulate all Content Controls that work across all Word hosts.