Shelter may have been taken down a while ago, not sure if by Google or the developer.
According to the Island developer Island was removed because it’s not supposed to use
REQUEST_INSTALL_PACKAGES, so it’s probably the same for Shelter. They’re appealing but if/when it returns it might be “with limited functionality” which one would be able to restore with an “extension” downloaded on github but at that point why not just install the apk from github in the first place.
As for Shelter and Insular (fork of Island), they’re also available on F-Droid.
Wonder if they’re cracking down on these “hacks” to leverage the work profile on purpose, like they do local VPNs that block ads.
Both use android’s work profile feature to isolate apps from the main profile, for example, If you install tiktok on island, and whatsapp on main, neither WhatsApp or tiktok will be able to see each other, among other kinds of data
It doesn’t directly, but some banking apps detect magisk in the app list, so even if you’ve added the apps to the exception list in magisk they’ll refuse to launch.
Installing the same apps in the work profile makes the magisk app inaccessible/invisible to them, which allows them to start up normally.