By the time Betsy Durkin appeared on DS, they had done such a hatchet job with Victoria Winters' character that I don't think anyone could've saved her. Alexandra Moltke's final episodes weren't exactly high points for the character either.
It will be interesting to hear a new perspective at the Festival, and she certainly wouldn't be the first actor with a very limited run on the series to make a Festival appearance. Paul Michael has been to at least two Festivals in recent years, and I know at least one of the series regulars didn't have the foggiest notion who he was when he showed up even though they worked together.
From a personal perspective, I would also point out that Betsy Durkin Matthes seems to be a very gracious, well-mannered person. I recently posted information about her book on my DS Alumni site, and I had the release date wrong because Amazon had it listed incorrectly. She contacted me with the correction, and she thanked me
profusely for mentioning her book on my web site.
Besides all that, I'm for any additional programming at the Festival that will cut into the possibility of Millay telling that damn trapped at Lyndhurst story again.