The idea being the non tapered will scrape the water off more efficiently. Maybe in a controlled environment you might notice a difference. I would be more aware of using heavy metal/ceramic shoes. They do have gripping power but have better metal than the drums. When a wheel cylinder sticks or park cable holds they eat up the drums. So just be aware if brakes indicate any dragging , repair quickly..
Got me thinking perhaps metal spray might restore drums too? And what if they could be hardened?
Above is a picture of my custom linings that I have been selling for 15 years. they are very soft and will not ever hurt the drums.
They will not last as long as originals but work 100% better. THEY STOP the car when wet!
Come to Florida for a ride with me and I will prove it.
I have a few sets with me in Fl.