For Myanmar, having "De facto independent areas (e.g. Wa state)" at admin_level=3 is wildly ambitious, since not only are these boundaries constantly shifting slightly due to the ongoing civil war, the actors involved don't even necessarily have the state capacity to accurately demarcate their own territorial claims.

The Wa State in particular appears to have undergone some "boundary fixing" a few weeks ago https://www.openstreetmap.org/relation/9399863 but whether it now accurately reflects realities on the ground is anyone's guess. I'm inclined to believe the Wikimedia map https://commons.wikimedia.org/wiki/File:Myanmar_civil_war.sv... showing Tangyan in Wa State territory is more up-to-date, unless they withdrew for some reason without it making the news. (The most recent I could find is this article from March where they were mining quartz in the area: https://english.shannews.org/archives/29385 )