I also found docs about aircraft but not airports, i suppose you refer to this:
%sdkfolder%/Documentation/02-Asset_Creation/3D_Models/Modeling_Practices/02-Levels_of_Detail.html
I am also wondering about airports, and if there is a setting or magic that can be selected to prevent runways to become a blurry blob at almost any distance except the immediate runway section that you’re rolling on?