I would second your request. The common failure mode is "fail-open", due to a broken winding. I would imagine that, similar to power transformers, a winding short (i.e. "fail-short") would also be possible due to insulation deterioration (overheating, moisture, etc.). I've been attempting to research and will respond if I find something. I'm hoping some folks (manufacturers or heavy users) will respond with some actual failure data/experience.