Can 'install' portable application to path that includes "Program Files" string, but cannot launch

Description: I recently downloaded LibreOffice version 25.2.3.0 Portable MultilingualStandard (*.paf.exe). I am running Windows 10 (x64).
Today I ran the EXE file and chose to install to C:\Program Files (portable)\LibreOfficePortable Note that while C:\Program Files is a system folder C:\Program Files (portable) is a folder that I created myself, with no special properties.

The EXE file 'installed'/extracted all of the files to the specified path.

However, when I tried to launch directly from the end-of-installation dialogue box, or when I try to run any of the 'installed' EXE files, I get an error:

LibreOffice Portable cannot be run from inside C:\Program Files.  This location is for standard local software only.  Please use this application from another location.  

Steps to Reproduce: 1. Download portable installer 2. 'Install' to "C:\Program Files (portable)\LibreOfficePortable" 3. Try to run application.

Actual Results: Unable to run application.
Get error in message box:

LibreOffice Portable cannot be run from inside C:\Program Files.  This location is for standard local software only.  Please use this application from another location.  

Expected Results: There are THREE problems:
(i) The documentation does not match the behaviour. If there is a need to prevent installation into paths such as "C:\Program Files (portable)\LibreOfficePortable", it should be specified in the documentation.
(ii) The portable installer allows extraction of the files to a path from which they cannot be run. The criteria to assess the path should be the same for the installer as for the launch algorithm. If the application would not be launchable from a specified path, then the installer should EITHER refuse to extract to that path OR extract only after showing a warning to the user and asking for specific confirmation.
(iii) The launch algorithm seems to be incorrectly checking only the first few characters of the path, rather than properly assessing what the top-level directory actually is!!! This is indicated by the display of the wrong information in the error message!

Reproducible: Always

User Profile Reset: No

Additional Info: "Known issues" Long Paths and Odd Characters - LibreOffice doesn't like running from overly long paths. So, while it will work directly from your desktop... if you have it within a subdirectoy on your desktop, it will probably fail claiming that some files are corrupted. LibreOffice also doesn't like certain characters like dollar signs in the path. This is why it's best to have the LibreOfficePortable directory in the root of your drive, or within a PortableApps directory in the root of your drive. The launcher attempts to check this for you and will let you know. https://portableapps.com/support/libreoffice_portable

Unable to copy here the information from menu Help - About LibreOffice, because I cannot run the application :-/ It's obviously not related to the UserProfile.