Given that Puyallup and the Tir Border is a bit more leaky makes this sourcebook of interest as I have a collection of escapees holed up in Puyallup working on creatinga 'Nob hill' section and paying off KE to patrol the area.
Just remember that getting from Seattle to the Tir involves TWO border crossings. There's a nice chunk of Salish land between Puyallup and the Tir border, afterall. Also, most of the southern area of Puyallup is Tarislar, which is already home to a lot of Tir refugees and expats.
And the book says that the official border crossings are looser, but you can bet that getting through in places that aren't so 'official' is still going to be tough, and if you get caught, you're still going to get dosed with Laes and dumped naked on the other side of the border, if you're lucky. If you're unlucky, Ehran's old Paladins will be the ones to find you, instead of the Peace Force.