I *think* the one named "Loww-scene static.BGL" looks like the correct one, and it's size if not too large that would cause GSX to reject it so, there's no reason why GSX wouldn't use it, unless is made in some kind of non-standard way.
So what I found in the Couatl.err file, as GSX continues to load the generic .BGL file instead of the gaya one even after I gave the exact path in the .ini file and made it read-only is following:
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\ContentInfo processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\MarketplaceData processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\scenery processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks\LOWW_Jetway processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks\LOWW_Jetway\model.Corto processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks\LOWW_Jetway\model.Largo processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks\LOWW_Jetway\model.Largo_w processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks\LOWW_Jetway\soundai processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\SimObjects\Landmarks\LOWW_Jetway\TEXTURE processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\scenery\Gaya processed in 0 seconds
File \\?\D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\scenery\Gaya\Vienna\modelLib.BGL skipped, likely too big to be an airport
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\scenery\Gaya\Vienna processed in 0.01 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\scenery\Gaya\Vienna\TEXTURE processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\MarketplaceData\gaya-simulations-airport-loww-vienna processed in 0 seconds
Folder D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\ContentInfo\gaya-simulations-airport-loww-vienna processed in 0 seconds
So - the Loww-scene - static.bgl was skipped?
Furthermore I found:Warning: airport LOWW described in multiple BGL files without proper DeleteAirport record
Loading airport LOWW from \\?\D:\Games\MSFS2020\Official\Steam\fs-base-genericairports\scenery\0601\APX52140.bgl
Customization file C:\Users\jan_d\AppData\Roaming\Virtuali/GSX/MSFS\loww-af_cei.ini ignored: missing afcad_path entry
But I've entered in the .ini the following:
afcad_path = \\?\D:\Games\MSFS2020\Community\gaya-simulations-airport-loww-vienna\scenery\Gaya\Vienna\Loww-scene - static.bgl
and well.. there it is...
Thanks for your efforts in advance