Seemingly, when initiating GSX in Brazil with any of Paulo Ricardo's scenery, a CTD is almost always imminent. Especially after landing in any of the select airports of his scenery and including Tropicalsim SBGR
It's NOT POSSIBLE that GSX, by itself, would cause a CTD. This for a very simple reason: GSX runs entirely *outside* the sim, in the Couatl.exe interpreter so, in the worse case GSX crashed entirely, it would simply result in Couatl.exe quitting, but as an external .EXE, it cannot (by definition) crash another .exe, and Couatl.exe surely doesn't try to "attach" to FSX.EXE, which would need special permissions to do so, even if it tried that.
What is REALLY happening, instead, is likely that, due to a combination of memory-hungry airplanes and memory-hungry sceneries in that area, you are already VERY close to memory exhaustion so, just having the GSX vehicles appear, might be enough to cause an Out of Memory error.
That's would explain why you think it's GSX that is "causing" this, when it's not.