Weird Standalone Builder issue

[Paul Dupuis]

I'm on Windows 10, using LC 9.6.6, and building for macOS and Windows

I have a folder called "Utilities" and in it I have the Windows version 
of an open source video utility called ffmpeg (specific file is just 
called "ffmpeg.exe". In the same "Utilities" folder, I have the macOS 
version of ffmpeg (called "ffmpeg" with no extension)

In the standalone setting, under the Copy Files tab, I added the folder 
"Utilities" and then I build for macOS and Windows;

Results:
For Windows I get 
C:\Users\paul\Desktop\HR460-LC9xx\HyperRESEARCH\Windows\Utilities\ and 
in that folder I have BOTH "ffmpeg.exe" (windows version) AND "ffmpeg" 
(macOS version) as expected. I intent in the "on standaloneSaved" 
message to remove the one that is NOT for the target platform

For macOS, there is weirdness, as I get 
C:\Users\paul\Desktop\HR460-LC9xx\HyperRESEARCH\MacOSX\HyperRESEARCH.app\Contents\MacOS\Utilities\ 
with "ffmpeg" (the macOS version)
AND
C:\Users\paul\Desktop\HR460-LC9xx\HyperRESEARCH\MacOSX\HyperRESEARCH.app\Contents\Resources\_MacOS\Utilities\ 
with "ffmpeg.exe" (the windows version)

So, not what I expected? The Standalone Builder somehow places the macOS 
version of the utility in .app bundle in Contents\MacOS\Utilities\ and 
splits the Windows version out to the app bundle at 
Contents\Resources\_MacOS\Utilities\

How does it know that the file "ffmpeg" is a macOS compatible command 
line binary???

This is not a problem form me as I can use revDeleteFolder to remove 
Contents\Resources\_MacOS\Utilities\ on the mac build and revDeleteFile 
to remove "ffmepeg" from the Utilities folder on Windows and I am left 
with the right utility for the right platform. I could also just copy 
the utilities from the project folder each build during the "on 
standaloneSaved" message handler.

I am mostly curious as to why the Standalone Builder splits the 
files/folder for macOS and leaves them together for Windows?