I am not so sure about that. I had problems with missing textures and found the reason to be that I did NOT have my bgl and textures in the scenery/global/scenery path! When I changed the path to scenery/global/scenery for my buildings and objects the textures returned. They worked in a non-standard folder structure up until MSFS version 1.9.3 but after that the correct, standard folder structure is essential.
BUT - I am using a unique name for the BGL (not modelLib.BGL, but ICAO_lib.BGL) and that works fine and should cause no conflicts. You should not use ANY default names for your files, please rename them (MyAirport, MyCompany etc.) to somthing starting with your airfields ICAO code or something else unique!
Like this:
