I never know how things are until after I do them. So now I have posted my PS essay and find that there is much more to know before forming permanent conclusions.
And already I find there is a Giulio Cesare production by him which also has Lorraine Hunt Lieberson. I have ordered it and will report. By now virtually everything by Lorraine is published.
Then they tell me that in 1992 he directed Saint François d'Assise at the Salzburg Festival with Dawn Upshaw. I am fascinated.