That's ideally what I'd recommend but it can be a personal preference or due to size and type of space. Storing out of the bag is easier to have a loose roll and provides more airflow in case there is any moisture on the board, any of the equipment, or the bag, helping avoid mold. If you are storing it in the bag I'd recommend ensuring it's 100% totally dry, leaving the bag half unzipped and don't set anything on top of it. Storing out of the board bag gives a better visual reminder if something is set on top of it. I've stored my board both in and out of the bag.
