I'm about to buy a soft top for spring/summer use and will need to store my hardtop and dont want to buy a lift. Is it safe to store the top standing up leaning against the wall with the rear window on a towel?
Why not just look on some of the threads on here and buy or make a cart for it. It will be more secure than what you are saying, and be able to be rolled around if needed.
The cart is essentially just cloth with a support for the top part of the back-window. So long as it doesn't get knocked over you would be fine. Probably a good idea to put something under that part to support it like the carts do.