GSX and GSX L2 are always been free to use at all FSDT airports so, just install those together with KLAX.
The obvious advantage of this is, since a lot of objects/textures used by all our sceneries are shared between them ( jetways, docking systems, marshallers, etc. ) so, instead of duplicating them in each and every scenery installer, making the airport installers unnecessarily large, slower to download and slower to install, we keep them all together in GSX, so you install it only ONCE, so airports installer will be smaller and faster to download. And, when GSX is updated ( automatically thanks to the FSDT Live Update ), ALL sceneries will get improved objects/textures/features automatically.
Other developers call this "xxxx objects Library", we call it GSX, that's why it's free to use at our airports.