My quick thoughts based on my discoveries and this blog:
Let @RyanAtSense know you have captured a failing AC unit, and keep the old device around for a few more days so you can easily refer to it for any follow up
But don’t be afraid to discard it since Sense keeps around the data.
Plus Sense won’t automatically clean it up unless the old detection is interfering with new detections I’m kind of experimenting with what happens to old device detection AC here: