I haven't tested the monitoring. But if an uninstaller is doing a before and after scan, it is using snapshots, which is different to monitoring. Almost all uninstallers use snapshots. When an uninstaller monitors installations, it actually monitors the installer and sees what files and registry keys are being created. Install Monitor, IObit Uninstaller and Comodo Programs Manager are the only other uninstallers I'm aware of that use monitoring.
The problem with using snapshots, is that all changes to the system get recorded, even ones not made by the installer. So for example, if Edge gets updated in the background when installing another app, then the changes made when updating Edge will get included in the record of files and registry keys that were created when installing the other app. This provides a good reason to actually verify what an uninstaller wants to delete, before letting it remove anything. There are also issues with uninstallers that you monitoring. They may fail to monitor the installation of some apps and depending on how well the monitoring works, they may miss some changes that an installer makes.
