There are probably others but these guys seem to have a good following, Oregon City area.
My brother has had a 2006 Legacy Wagon (Manual) since brand new and has only taken it to his local Subaru specialist since day one, It was their recommendation to buy the Subaru over the list of Audi’s he had given them. But Harmony in Bellingham is quite a trip from Portland for service but hopefully you can find a similar shop.