Bad news -- sort of. It's been running like a top for a week but yesterday (a rainy day fwiw) the stalling out returned though only for a few minutes. The car was warm and after four or five attempts to start and feather the revs past stalling it forgot the problem and has driven great for two days. But obviously worrying. Here is video of the failed startup attempts: https://share.icloud.com/photos/0YQzTYa6tOJqDPG4qHqOFzpEw