That's what I was going to post - the crucial difference is that unsanctioned modification is a feature of Win32, but a bug in UWP.
I'm fairly sure it's an unintended side-effect of both. Have you seen how much some devs like Rockstar try to stop people modding their Win32 games? UWP is rather locked down but I think it's unfair to call it a bug that it allows modding. If they were so concerned about games being modded then they wouldn't leave plaintext files everywhere and the game itself would have an integrity check and refuse to start like they do on console, not just checking the files against servers by default.
If the files are on your computer and not a server then you can bet it's only a matter of time before you can mod them, whether the restriction is folder permissions like with this game or non-standard formats.
EDIT: I should make this a bit more interesting and show some stuff off:
Once you have access to the WindowsApps folder, this is how your apps look.
I have the Xbox App installed to this folder as well but that's irrelevant, what we're looking at now is the Apex one. Here's how the root folder looks. What's interesting to note is that the .exe will not run on its own. I assume apps execute things with certain launch parameters that make it function, but I still don't understand what you're executing when you click an app's icon. Ever since at least the 360 titles, Forza's assets have always been contained in this "media" folder you can see in this screenshot.
Inside the media folder is a multitude of asset files and folders. The one we want to look at right now is renderscenarios as most of the other files are odd formats or encrypted it seems.
Inside renderscenarios we have a PC folder, then in that we have a folder for each of the presets: low, medium, high, ultra. As I play on max settings I edit the ultra folder, here are the contents of that:
As you can see, there's a different XML document for certain "scenarios" in the game and the rendering options they should use, hence the name. The Xbox One also uses this format of configuration, because as you may have noticed, in a 1 car race your reflections and raindrops run at 60fps while with AI they're cut to 30. On the PC they're all unlimited once your settings are high enough, but if I wanted to cap them I would do it in one of these files. Here are the contents of photomode.xml:
Most of these variable names are probably just guesswork if you make changes to them, but a few are self explanatory. One of the major changes I made was to set "CarDrawAutovista" to true, meaning that in photo mode I now see the highest LOD version of my car, smooth wheel arches etc. Enabling that in the race scenarios is what messed up the car's cockpit model in the picture at the top of this thread, as there's no proper animated cockpit for autovista cars to use during a race.
Hope some of this was interesting to read.
