Upvote:2
Embassies and consulates almost always prefer you use the embassy or consulate of the country youβre a resident of. Even if there isnβt a legal restriction, theyβre more familiar with the documentation you might provide.
Given that there is an honorary Italian consulate located in Seattle: https://www.embassypages.com/missions/embassy7356/
You may want to email both the San Francisco and Seattle consulates and ask for their advice because as @Giorgio notes, not all honorary consulates can handle all services.