That's an easy thing to do, we might have remove the restriction completely, because it's not as if GSX would be doing anything other than requesting the airplane position.
The one and only reason for that option, was because there's a bug in P3D facilities.dll, that when flying over remote areas with almost nothing around ( like northern Canada ), just calling an API to ask IF there are airports around caused a CTD in facilities.dll, because that function as a bug in the sim, this spread the legend "GSX crashes P3D in Canada", when in fact the sim was crashing on its own because that API had a bug ( it didn't had any issues in FSX ), so to prevent this, we completely disabled GSX when cruising.
We don't even use it anymore now, both because it's just not there in MSFS, but also because we can now get the same data through Simconnect, officially, so that restriction is more a legacy feature that can be lifted in MSFS, or at raised.