oh ok, then it changes everything
we do not recommend installing things from unofficial repositories and we even discourage it.
we made some statistics about the most used unofficial repositories in parrot (by looking at support topics of people posting apt output) and we found that most of the people add the ubuntu, debian or kali repository to parrot and we made an apt hook that disables such repositories by default by setting up a very low apt pinning level to them.
the second category of people using external repos involves people using specific repos for unsuported software (i.e. latest nodejs, docker prior to its inclusion in debian, sts versions of nodejs, the repos pre-installed by the atom, vscode or steam debs etc)
we can’t really protect the users from such repositories because some of them don’t need security, they just need to develop software, play games or test things without hassle. and we don’t know what external repositories they usually configure
on a brighter note we don’t include PPA support and we don’t want to support it in the future, and our support team is properly trained to do psychological terrorism on people that use external repos and ask for help