My Oasis is the first reader that I've used without a cover. I initially tried a regular cover but preferred it without. I have a skin on it and a Moko sleeve for it (
https://smile.amazon.com/gp/product/B07CN3M955/) that it stays in when not in use. I only use my Oasis in bed, and I have a specific safe place for it to sit when it's being charged so it's pretty safe.
I do, however, still have the regular cover available if I ever decide to take it out of the house.