it might be useful to change the names of the installer files; now they are both called "gsx-p3d4-setup.exe". This explains my confusion.
What do you mean by "both"? There are only two installers and are:
- The 32-bit version for FSX and P3D1, 2, 3, which is has always being called gsx_fsx_setup.exe
- The 64-bit version, for P3D 4, 5 and 6, which has always been called, since the first P3D 64 bit came out in 2017, gsx_p3d4_setup.exe, didn't change name with P3D5 came out and didn't change name when P3D 6 came out.
It's not as if you could install the wrong version in the wrong simulator. If you start the 32-bit installer, it will show only the 32-bit simulators you have installed (and if you have none, it won't install anything) and if you start the 64-bit installer, it will only show the 64-bit simulators you have installed.