From WA Code
"...PROVIDED, That such regulations must contain a requirement that land in short subdivisions may not be further divided in any manner within a period of five years without the filing of a final plat..."
Question:
Given that you have just completed a short subdivision, can you immediately turn around and plat one of the resulting lots using the (full) platting process?
Of interest to the discussion would be the definition of a "final plat"...
"'Final plat' is the final drawing of the subdivision and dedication prepared for filing for record with the county auditor and containing all elements and requirements set forth in this chapter and in local regulations adopted under this chapter."
(The context is a city, but their code mirrors the state code.)