As far as I understand it, in the context of large structure formation, the interplay between gravity and cosmic expansion can cause certain anisotropies in voids that can make them collapse (https://arxiv.org/abs/astro-ph/9601026)
Can something similar happen to superclusters as well?
It is expected that many superclusters have their major components gravitationally bound and significant fractions of them will collapse. These secondary structures could be referred to as "survivor" clusters, evading Expansion's separating properties. Shapley SCI 124 is a most likely candidate, being noticeably overdense (red-shift: 0.046) within the Centaurus constellation. Indeed, Shapley's central region may already be showing signs of collapse because density ratios there are higher than required for overcoming Expansion.
Bear in mind that a supercluster may not collapse into a single new object but several. Also that Laniakea (Shapley's neighbour) will disperse, not being gravitationally bound.
Because the density of dark matter is higher in superclusters, most of these will also be subject to the same forces favoring disintegration which currently are holding the supercluster structures at large scales. To elaborate a bit, the superclusters, being largely matter dominated, are supported against over-densities in the hot and warm cosmic soup in which they are immersed, by additional forces from the galaxies and gas clouds in them. The well known linearly increasing temperature of the cosmic background radiation measured in the microwave may be due to the collective action of the dark and baryonic matter in the clusters and superclusters of galaxies and their precursors. However, these considerations are valid over very different scales, some of which we can measure in a laboratory. The core of a neutron star may be held up against it's own gravity by the Fermi degeneracy pressure exerted by the particle or quasiparticle quantum states of the neutron star. The superclusters being very big on the cosmic scale would be like the neutron star in this regard. So gravity is likely to win the fight. The result would be the collapse of one part of the superclusters to form a more concentrated bound object. This is not enough to answer your question. You would need to know of a cluster which has a reasonably denser concentration of galaxies than it's surrounding regions. However, there is research which may help you identify a giant halo surrounding a small galaxy. This is a "dark core" of some kind of dark matter and dark energy. Just imagine for a moment that dark matter does have baryonic clumps (or doppelgangers) around. They have cosmic conductivity, if they did not, this cosmic web would not work. So electric fields and electric currents would form and would generally align to the direction of the magnetic field lines. If you were tracing the magnetic field back, it would also roughly align to the direction of expansion of the universe.
