Add Environment Variable to MSIX package using PSF Fixups in Packaging Tool - what am I missing?

Hi everyone,

I am currently testing packaging apps into the MSIX format and have been successful for any simple installers.

Now that I am trying to package more advanced installers I have to utilize PSF Fixups, in which I have issues with the Environment Fixup.
Even though I have read up on previous discussions regarding this, I simply cannot get this fixup to be successfully added and recognized within the MSIX App.
I am judging this based on that the same app will tell in its own app options whether the environment variable is available or not.

Some key info (Tried attaching several screenshots, but it wilI not let me. Hopefully the necessary information comes across):

• Using MSIX Packaging Tool version 1.2024.405.0
• Using the included PSF Fixup for Environment Variables within MSIX Packaging Tool.
• All PSF Fixup files are included in the MSIX Package.
• In the manifest file the executable "PsfLauncher64.exe" is pointed at.
• Basically, the config.json is formatted in the following way if I were to change out anything referring to the actual app name.
  

What am I possibly missing out on or have misunderstood here? Any help in leading me into the right direction is very much appreciated, thanks!