I have plenty of custom-made ADE in my P3D and I'm just wondering if GSX uses ADE links and taxiways to navigate its vehicles OR GSX uses its own logic for trucks and vehicles movements.
GSX always uses the AFCAD, which is the only place it can find information about the paths where vehicles can move. It's obviously using its own logic, but the data source can only be the AFCAD.
The problem is that I have a lot of ADE tricks for add-one sceneries to make AI movements more effective. While it's good for AI it could have devastating effect on GSX,
If with "ADE tricks", you mean such abominations like the "plumbing" technique, then no, using those methods IS asking for trouble. However, GSX gives a way higher weight to *VEHICLE* paths, so it tries to use those, and will use taxiways only when there's no other path.
Which means, if you want to use your custom made AFCADs, if you edit them in the proper way, by being sure that *vehicle* paths allow vehicles to reach all parking, GSX will use them by preference and shouldn't be affected by convoluted/abominated/plumbed taxiways.
Of course, this assumes you don't also introduce *errors*, like orphaned parkings, overlapping nodes, orphaned nodes, etc., which will surely result in problems, and not just with GSX.