Couatl and Addon Manger don't have anything to do with this, of course. As powerful as they are, they surely cannot expand the limited memory of your video card to allow you to enjoy better settings, and P3D V4 obviously requires more VRAM than V3.
The settings that help to reduce blurred textures are:
- The texture resolution slider. KLAX is designed using few 4K textures instead of many 1K textures so, it requires the texture resolution to set at 4K, otherwise you won't see the scenery at the resolution it was designed for.
- The Anisotropic filter. This should be enable and, possibly, set to 16x to enahance the application setting, in the video card control panel.
But the main issue is, a 2GB card is a bit too low for P3D 4.