An estimated one octillion universes form the main Hospice network, though it is expanding all the time as the Cascade's leaders intervene more and more throughout the omniverse.
The Hospice's universes resemble "conventional", natural universes filled with galactic filaments and superclusters, but they are somewhat different in their actual organization. The first thing one will notice upon entering is that there is no redshift: Hospice universes do not expand, as the outward acceleration due to dark energy is matched precisely by the inward acceleration from gravity. Advanced computing systems monitor mass-energy entering and leaving each universe, and adjust the amount of dark energy to match by moving it to and from adjacent universes - of course, they are programmed not to affect universes containing life, so as not to disrupt it.
Galaxies move around and collide in these universes, but just as often they are dispersed by long-range gravity controllers back into large clusters of dwarf galaxies and nebulae. Inhabitants are kept aware of any changes that may be occurring to their cosmic neighborhood, and given the opportunity to move temporarily or wait out the adjustments.
Stars are born and die as usual in these universes as well. However, if the computers and sophonts watching over interstellar space detect an excess of metal in the interstellar medium, physics manipulators will disperse it back into hydrogen to allow for the stellar cycle to continue uninterrupted. Because of how this process is performed, galaxies can contain roughly equal mixtures of Population I, II, and III stars, which would otherwise be tremendously unlikely.
Sadly, there are eldritch monstrosities, cosmic overlords, and enterprising civilizations at risk of harming the sophonts within the Hospice's universes; thankfully, the Folded Cascade's leaders anticipated this, and built in a series of hyper-powerful defensive systems to keep them secure.
Similarly to the Cascade itself, the Hospice's universes are protected from outside access through the Interdimensional Void by a storm of Planck-scale stringshard drones engineered to remove whatever they contact from the timeline. Portals to all but a handful of well-defended relay universes are sealed off, and all connections are monitored, allowing for a torrent of weapons fire or an army of drones to be deployed through a dangerous portal.
In the event that entities within these universes go to war against one another or attempt to violently break out, peace is kept through the same automated physics-manipulators that maintain the universes' balance. Offending entities often find their FTL drives disabled, their armor disintegrated, or, in suitably drastic situations, their minds wiped.
Guardians are the main enforcers within the Hospice, whose mission is to maintain peace and exterminate threats within it. Guardians are programmed to be unbiased in their decisionmaking.