Found this while browsing and wanted to add my two cents: have you checked if there have been any app updates or firmware updates for the M30T since your original post?
Sometimes support for new features is added in updates
You might also want to reach out directly to DJI support to see if there's a workaround or alternative solution. Curious to hear what you find out!
The M30T might not be fully compatible for that task yet
You could try using a custom mission in DJI Pilot 2 or check for firmware updates to see if they support this feature soon