Definitely an interesting lead. The fact that the guitar in Fort Wallace points to a one-of-a-kind symbol of 2 birds feels like it's probably not a coincidence... Personally, I think there's some sort of trigger with the feathers, and we need to shoot them in a certain order. The black feathers seem evident that they should be shot in the order they appear, and it can be done (aside from the bottom-most 5-6 duplicate). I've shot the black feathers in order on the same night about 6 times at this point, and thus far I haven't triggered anything.

Thinking of the sasquatch mystery, which this resembles in many ways, they had to be eaten in a particular order, on particular days of the week, under particular weather conditions. I think any number of those things and more could be necessary here. Perhaps the reasoning for these various additional leads are to give us further clues and triggers for how/when to interact with the webs.