I'm not playing through Dunwich yet, but I am working on an app for the token bag so it got me looking at the setup. I wanted to confirm what you add to the bag - it looks like it adds a single token based on the difficulty, but it also says "Add the following chaos token(s) to the bag". The (s) seems odd since each difficulty only adds a single token, which makes me wonder if you add everything up to that difficulty (i.e. Standard adds a -2 and a -3)?

Anyone confirmed this one way or the other?

Nope, just add the one token for your difficulty level.