I regret deleting a deck. I went through the process of downloading all the decks I currently have, then doing Switch Profile > Open Backup … but the list of backups available in the backups folder stops ~1 week after the period of time I was looking for when that particular deck still existed.
I’m guessing it’s just a case of “tough luck”, but thought it was at least worth asking … is there any way to retrieve an older backup or will it be truly gone?