https://www.amazon.com/Compact-MoKo-...aura+one+cover
Got the Moko cover and can confirm that the sleep function works now. I'm not sure if this is because of any firmware updates or if Moko changed their cover model (this seems to be a new listing. you can still find the old one for $8.50). There is a slight new fake leather smell right out of the box but I'm guessing that'll go away soon enough. It covers up the reader pretty well and seems to be reasonably sturdy. I like it.