. . . after a short ride where I got rained on tonight I noticed a bit of water dripping from the end of the snorkel . . . I do plan on making a screen that goes over the end from the same kind of thing that protects the radiator to prevent bugs . . .
Action starts when water is flowing from the forward end of the snorkel like a fire hose. :giggles Water generally ends up as vapor. Using the same size mesh for the intake end of the snorkel as the stock radiator shroud uses is worthwhile to keep mice from making nests on the floor of the air box.
I don't worry about any of this stuff. The air filter and box are large enough to handle incoming insects, desiccated mouse bones, gravel and sand while still delivering performance. Oversize debris drops to the floor of the box. On a naked bike, it takes all of five minutes to remove, clean off and replace the filter. Cleaning the floor of the air box is more involved; if you don't let guests look in there, you avoid it. :yes
Enjoy the ride.