This is not “blur” for performance. Instead FS2020 is limiting the maximum LOD it is loading based on the distance to the tile and the relative tile size on the screen. Unfortunately it is also distributing the various LOD rings ranges too close to the aircraft.
It is therefore not blur and I’d suggest you review the following information (and vote):
LOD Problems - Distances revisited - Bugs & Issues / Scenery - Microsoft Flight Simulator Forums
This table is showing at 600m from the texture, you’re already using a texture resolution which is 64 times smaller than below 75m… imagine at 30000ft…