Thank you Esteban - that's exactly what I'm doing now. Generating the index in JSON format and then manually translating it to XML. It's very inconvenient and prone to human error. Since I (and likely others) would greatly prefer a working tool, then I will raise an issue on that link that you share...

 I see a similar issue is asked on this forum, so I thought I'd raise my problem here to hopefully find the owner/manager of this tool.https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/oak-index-definition-generator-url-not-working/td-p/634336  We deploy indexes as .content.x...