OOP background task in WinUI/WinAppSDK desktop app which is published SelfContained doesn't run on a clean Windows machine

[JosHuybrighs]

I have a WinUI/WinAppSDK desktop app with a couple of OOP background tasks which run without issues on a device with .NET installed (by the user, from Visual Studio, etc.) but which don't run on a client device that doesn't have .NET installed. The app is published as SelfContained and the msix contains all the necessary dlls.
The OOP background tasks are setup as described in the discussion that I also started about this problem on WinAppSDK github. See #4115.

Not sure but I would think that windows backgroundTaskHost.exe is missing some information (dlls, winmds, ..) in order to address WinRT.Host.dll and from there the BG task.
Event viewer reports error 0x80008083 and the BG task is not being started. ProcMon shows that backgroundTaskHost.exe stops after trying to ceate a ..\AppData\local..\ AC\GEH\POF.dat file.

Is this something that has been overlooked?