GSX with modified AFCAD

Hello,
I am using some modified AFCAD files made by Ray Smith/Robert Catherall which can be found on avsim for some P3D airports. I am using P3D v4.2.
It looks like the sim is correctly reading the files as they modify the airports (gates, taxiways, ...).
However, it seems that GSX does not manage to use the modified AFCAD and still uses the default AFCAD.
As a result, when I am loading a flight at a gate, GSX does not recognize the gate the plane is at. When I open the GSX context menu, it does not recognize the gate and I have to manually select it. Once the gate is selected in GSX, it moves the plane to a slightly different place.
Looking at the GSX menu, it looks like GSX is reading the AFCAD which is located in the Prepar3D\scenery\... folder whereas my modified AFCAD files are located in a folder outside Prepar3D. 
I also use some payware airports GSX works perfectly with them (it reads the modified AFCAD).
I would like to know if some of you are using modified AFCAD with GSX and how to make it recognize the modified AFCAD.

Louis DAVID