I’m absolutely delighted (and not a little relieved!) to say that Chris’s suggestion worked just like it should.
I set all the render controls on the HDV timeline to ProRes422 (HQ), rendered, and exported to a QuickTime Movie using ‘current settings’. Made me an utterly lovely 42GB file, which with a bit of judicious compression markering, has now been burnt onto DVDs.
I love when a workflow finally comes together! Thanks Chris; thanks Cow.