For this very reason I wish there was a different flag for pacman, which would allow to effectively differ between packages installed for the base system itself

For this very reason I wish there was a different flag for pacman, which would allow to effectively differ between packages installed for the base system itself, and for the local packages that can be installed and wiped without bricking the system afterwards. Similar to how a rootless system works on MacOS, where restoring the OEM state involves just wiping the folders (e.g. /usr/local) with the differences that override changes to the base system. But for that to work, we desperately need a different POSIX incompatible filesystem structure, because /etc/ has to become /local/etc or something like that. /usr/local is theoretically there but on most distributions /sbin and others are just symbolic links these days, so they are pretty much pointless.