Sounds marginally useful. Not sure why you don't delete them yourself.
I no longer download from third-party app collections. It's either the App Store or the dev's site. Even paranoid folks have enemies!!!
I think most apps have "Uninstallers" that will also remove their ".pkg" files. Even Apple did that a couple of OS installers a while back, but they did it as part if the
installation process. "So, you want to try another install? Go download it... again!"