Neutron star jets move at one-third the speed of light
phys.org
phys.org
It's only indistinguishable in its mechanical aspects, however. Once you start looking at its thermal and electromagnetic behavior it's very different from how solids behave.
I would agree with you about the inner crust, and so would Chamel (and many others): "Unlike the situation in ordinary solids (ordinary meaning under terrestrial conditions), the electronic properties in neutron star crust are very simple. The matter density is so high that the Coulomb energy of the electrons is negligible compared to their kinetic energy" [which is essentially your point] "The electrons can thus be treated as a degenerate relativistic Fermi gas." Chamel 2008 is also excellent <https://link.springer.com/article/10.12942/lrr-2008-10>.
More recently Taverna et al 2022 <https://www.science.org/doi/10.1126/science.add0080> does X-ray polarization spectroscopy on candidate magnetar (Anomalous X-Ray Pulsar AXP) 4U 0142+61 <https://en.wikipedia.org/wiki/4U_0142%2B61> (follow links in [6] therein) to investigate the physical state of the crust, finding the best match is a solid and bare surface.
Finally, the phys.org article at the top corresponds with Russel et al 2024 <https://arxiv.org/abs/2403.18135> which as far as I can tell has practically nothing to do with this thread of discussion nor the paragraph in the phys.org article that motivated it. Perhaps the phys.org article writer confused accretion "hard state" (relatively low mass accretion rate, p. 3 of Russell et al. 2024) with a stiff (or hard) outer crust equation-of-state which compresses poorly compared to an EOS softened by neutronization (e.g. Haensel, P., Potekhin, A.Y., Yakovlev, D.G. (eds) (2007), chapter 3 <https://link.springer.com/chapter/10.1007/978-0-387-47301-7_...>).
The excellent overview and somewhat different approach to the NS EOS in Sumioshi et al 2022 is pretty neat too <https://arxiv.org/abs/2207.00033>.