I am not sure you could safely build a "tent" to avoid puddling without endangering your liner. I suppose you could go nuts and buy enough pillows to fill the entire surface of your pool, and as long as they were taller than the pool side you would get some drainage. However, once again snow would not drain off, and any dips or valleys in your cover between pillows would suffer a lot of pressure and potential damage. The point of the "pillow in the middle" with slack in the cover is so that the cover is always supported from underneath by the water/ice or the pillow, and its not pulling too much on the pool sides. Puddling may just be an unavoidable consequence.