  We analyze the compatibility of the hypothesis of third-family quark-lepton
unification at the TeV scale with electroweak precision data, lepton flavor
universality tests, and high-$p_T$ constraints. We work within the framework of
the UV complete flavor non-universal 4321 gauge model, which is matched at one
loop to the Standard Model Effective Field Theory. For consistency, all
electroweak precision observables are also computed at one loop within the
effective field theory. At tree level, the most sizeable corrections are to
$W\rightarrow \tau\nu_\tau$ and $Z \to \nu_\tau \nu_\tau$ due to integrating
out a pseudo-Dirac singlet fermion required by the model for neutrino mass
generation. At loop level, the new colored states of the model generate large
flavor-universal contributions to the electroweak precision observables via
leading- and next-to-leading log running effects, yielding a significant
improvement in the electroweak fit (including an increase in the $W$-boson
mass). These effects cannot be decoupled if the model addresses the
charged-current $B$-meson anomalies. Overall, we find good compatibility
between the data sets, while simultaneously satisfying all low- and high-energy
constraints.
