So I backed up a copy of the original "CvxExtractorGui.exe" into a ZIP file.
Next, I Drag-N'-Dropped the original "CvxExtractorGui.exe" onto "4gb_patch.exe" to set that flag.
Then I repeated the test of extracting [FSX install path]\Scenery\1002\scenery\cvx8419.bgl
...with intended output of a ESRI SHP file.
The test with the "4 GB Patch" applied to set the LARGE_ADDRESS_AWARE flag was successful !
This was the status of processing when the task completed:
I then successfully Appended all of the SHP files output by "CvxExtractorGui.exe" to the 64-Bit FS scenery utility.
IIUC, the "4 GB Patch" applied to set the LARGE_ADDRESS_AWARE flag may fail on some 32-bit EXE's, largely due to DLL dependencies; however, I suggest this merits testing for compatibility to update "CvxExtractorGui.exe".
Many thanks again for making CvxExtractorGui available to the FS development community.