  In this addendum to "$B_s$ mixing observables and $|V_{td}/V_{ts}|$ from sum
rules" \cite{King:2019lal} we study the impact of the recent improvements in
the theoretical precision of $B$ meson mixing onto CKM unitarity fits. Our key
results are the most precise determination of the angle $\gamma =
\left(63.4\pm0.9\right)^\circ$ in the unitarity triangle and a new value for
the CKM element $|V_{cb}|=(41.6\pm0.7)\cdot10^{-3}$.
