Removal of an AppX/MSIX package leaving unwanted clutter in the user registry.

MSIX is supposed to be a clean uninstall.  However, I have some detected some unnecessary garbage left behind when uninstalling under HKCU\Software\Classes.

Take a package and install it.  Then Uninstall it.

Repeat that a few times.

Open Regedit.  Browse to HKCU\Software\Classes.

Do a find on the package name,.

You will find there is a key starting with AppX (followed by random looking letters) with subkeys Application, DefaultIcon, and possibly Shell.  These were added during the installation of the package.

Keep searching (F3).  You will find the same information under an AppX... key for each package you originally installed.

This does not appear to be due to delayed removal, as they remain weeks or months later.