Do these parking markings look like 2048 texturing or are these as default on KLAX v2 ?
KLAX has been designed to use 4K textures so, if your resolution in the sim is lower than that, you are not seeing the scenery as its maximum resolution.
Also is there a specific or recommended antipopup value to use ?
No, because it depends on your system, your settings, other addons installed, and your own personal preference of frame rate (low anti pop-up) or smoothness (higher anti pop-up).