To clarify, GuixSD is a distro that is based on the Guix package manager. If you install Guix (the package manager) on Trisquel and do not enable binary substitutes, the Guix package manager is rolling and sources-based even though Trisquel is not.
Guix (the package manager) uses tarballs, which you say are acceptable. This is true whether Guix is used in GuixSD, Trisquel, or any other distro.
