Sometimes it’s good to be able to find the internal locations of Modern app shortcuts so you can manually remove them. This is especially true if the shortcuts are broken as below:
Fortunately, said shortcuts are located within the subfolders at C:\Users\YourUsername\AppData\Local\Microsoft\Windows\Application Shortcuts.
A word of caution here: unlike with desktop apps, the Modern app shortcut folder names don’t necessarily match their corresponding app names verbatim. Therefore, instead of deleting, you might want to simply move a suspected offending shortcut folder to a different location first and then check the All Apps listing – which updates in real time – to ensure only the desired shortcut was affected.
Hopefully Microsoft enables easier manual removal of bad shortcuts soon.
Thanks dp1985 for this solution.
EDIT: If you removed a corresponding folder and All Apps didn’t update, restart Windows Explorer from Task Manager.