  We numerically study quenches from a fully ordered state to the ferromagnetic
regime of the chiral $\mathbb{Z}_3$ clock model, where the physics can be
understood in terms of sparse domain wall quasiparticles of six flavors.
Similar to the previously studied models, ballistic spread of entangled domain
wall pairs generated by the quench lead to a linear growth in entropy up to a
time $\ell/2v_g$ in size-$\ell$ subsystems in the bulk where $v_g$ is the
maximal group velocity of domain walls. In small subsystems located in the
bulk, entropy continues to further grow towards $\ln 3$, as domain walls that
cross the subsystem increment the population of the two oppositely ordered
states and restoring the $\mathbb{Z}_3$ symmetry. The latter growth in entropy
is seen also in small subsystems near an open boundary of the system in a
non-chiral clock model. In contrast to this, in the case of the chiral model,
entropy of small subsystems near an open boundary of the system saturates. We
rationalise the difference in behaviour in terms of qualitatively different
scattering properties of domain walls at the open boundary in the chiral model.
We also present empirical results for entropy growth, correlation spread, and
energies of longitudinal-field-induced bound states of domain wall pairs in the
chiral model.
