  We study universal features of the hydrodynamization process in heavy-ion
collisions using QCD kinetic theory simulations for a wide range of couplings.
We introduce the new concept of limiting attractors, which are obtained by
extrapolation to vanishing and strong couplings. While the hydrodynamic
limiting attractor emerges at strong couplings and is governed by the
viscosity-related relaxation time scale $\tau_R$, we identify a bottom-up
limiting attractor at weak couplings. It corresponds to the late stages of the
perturbative bottom-up thermalization scenario and exhibits isotropization on
the time scale $\tau_{\text{BMSS}} = \alpha_s^{-13/5}/Q_s$. In contrast to
hydrodynamic limiting attractors, at finite couplings the bottom-up limiting
attractor provides a good universal description of the pre-hydrodynamic
evolution of jet and heavy-quark momentum broadening ratios $\hat q^{yy} / \hat
q^{zz}$ and $\kappa_T/\kappa_z$. We also provide parametrizations for these
ratios for phenomenological studies of pre-equilibrium effects on jets and
heavy quarks.
