Whilst oil being flung around by the crank and gears could be a problem, don't forget, the sump filter is completely emersed under the oil, dampening the effect of the ebb and flow of oil, I think oil being flung aroumd and damaging the filter would a minor problem, rather being flung aroumd the oil would be moved aroumd in a fashion similar to a washing machime.,
Consider: Oil is at its thickest when cold. And when oil sits, contaminants will settle to the bottom. Being as its only the flimsy straight mesh on the filter that is damaged, Cold, thick oil, rich with debris at its lowest point (around the filter) would be a primary cause. Cold starting with dirty oil, add in a swishing motion, perhaps this is the recipe.
I personally don't like the idea of an extension to the sump plate, it provides a reservoir for oil thick with debris to collect, and being such a small area amd well below the crank its doubtful this oil would mix freely with the oil above. Perhaps with very frequent oil changes it may be of benefit, but who wants to change their oil every 5 minutes.
Just my two bobs worth.