But my p3dv4 scenery is installed into d:\addon manager not d:\p3dv4 Will the path still work?
Of course it will, and you can get confirmation for this, by checking the airport customization dialog, which will tell you what .INI is being used.
The path there is entirely irrelevant. We left it, just as a remark for you of *where* the AFCAD was, when you originally created your customization, but the program doesn't use it, only the file name matters, so the customization will work regardless where the scenery is installed, as long the AFCAD name matches.
In fact, I believe this is explained at Page 32 of the GSX manual, in the notes for scenery developers.