I have no concern on the selection of the secondary belt cleaner/ scrapper, so long we design the spring rubber strength sufficiently to make sure intact between belt and scrapper surface.
However for the plough cleaner, we need to ensure the belt internal is always intact with the plough surface. The spring rubber strength must be designed sufficiently, especially the belt length is very long.
Also, I think a "D" plough is more suitable than "V" plough. Because it deflects the material only to one side (easier to clean), and it fits better with a reversible belt.
What do you think?