Yes, this is a good discussion topic, because it addresses a problem that is often fatal to the 240, even where you live, the best place in the world for decent 240s. Trees.

You and I have been thinking about this for some 20 years I guess, and still nothing, besides taking some of those trees and building a garage.

I don't envision the snow caps being much use to keep the clogging leaves and seeds out of the flow-through ventilation system unless they themselves have screens to clean. I look at the accumulation under the sun roof cover on a parts car. The wind drives debris into every crack. That stuff doesn't fall straight down.

Someone more creative than I am could design a durable plastic screen attachment to be fitted in or threaded under the cowl slots. And yes, 3D printing would make prototyping and versions to fit all three cowls affordable to the hobbyist.
--
Art Benstein near Baltimore

"The most beautiful peonies I ever saw," said Paul, "were grown in almost pure cat excrement." -KV