Can't ask a dumb question; a question not asked is another story.

I can't provide a clear answer to your question, but I can say that evaporation will cool the water so breezy and dry call for the cover. The pool lose less heat when covered when the air is cool and there is no sun. Cold rain will cool the pool covered or not. On the other hand, the solar blanket would slow heat transferred from hot air and radiant heat from the sun. Where the balance is I can't say.

For what it's worth, I keep the blanket on when we're not using the pool.