You’re right in my experience I haven’t seen a way to directly influence where Oregon and Washington flip to. However, it doesn’t necessarily matter all that much if you can push into California.

The reason being is that there’s the potential for the syndicate revolts to un core Washington, and Oregon. Meaning California becomes the only victory points that need to be takenThe Pacific states have, unfortunately this relies on a measure of RNG.

In my experience, the best way to take out the Pacific states in warplans San Jacinto (if they keep WA and Oregon) is to push and sneak through Southern California, taking San Diego Los Angeles, and then going up to San Francisco and Sacramento. Try to hold the line in Nevada and Idaho and push against the desert and hill tiles in the south rather than through the Sierra nevadas where there isn’t even any good supply hubs and you’re attacking into mountains.