As explained so many times, GSX cannot possibly "hang" the sim, because it runs entirely separate from it.
Instead, there's a known bug in the P3D 5.1 new Simconnect Html menu, which hangs by itself, without this having anything to do with GSX, but can easily mislead users assuming it's GSX's fault, because users always associate what is really the "Simconnect menu", to be the "GSX menu", but of course the problem happens with every add-on that use it, and even with the default ATC window, it's just that opening it from GSX is done more often, so the chance the menu will hang is higher with GSX, just because you call it more often.
Some users reported that switching to the previous Scaleform-based menu, will fix the menu hangup.