. . . membership updated.

Not sure how you're going to put a cover on a roller in the middle of the pool, and have it cover the entire pool. I suppose you could make a roller system that rolls up a folded cover. One person could roll it up, but it would take two to spread it back out. And I think you'd have to build your own system.

I'm sure it could be done, but I don't recall having seen someone do it.