OK, Tried that. Result was a DVD with 12 chapters (or 13 for disk 2) that played the first 7 (or 8 for disk 2) then repeated the last scene until playback was aborted.
This was the exact same result I had with 'Thor' BEFORE version 8.1.2.0 Qt was released. Same quality issue, same excessive feature-length titles and same result when copying the title number displayed during playback on a standalone DVD player.
Is there anything else I can try?