Great and much needed article. I think we should be careful about suggesting alternative formats. Other alternatives would be to rethink your approach and implementation. I think there are rare cases where you would need to provide an alternative format and when one is required, rethink your design.
Question about the http://www.accessibilityoz.com/ implementation. I noticed a role=“listbox” but no children had role=“option”. Was this intentional? Or, maybe I’m missing something. If you could speak to the “role” ARIA plays with carousel accessibility that would be fantastic.