There are all kinds of weak things about the update manager/server thing for ESXi (requires a windows host and runs a database to keep track of a tiny number of patches, uses a kludgy plug in, can't have IP changed after setup, etc etc as if it is 1996 and I'm setting up NT), but it is flat out unusable if you don't have vMotion, and that means it is completely broken if you use Essentials. Quick, name another piece of software in this price range that cannot check for updates, download, and install them.
I have a simple setup, a racked Mac Mini host for OS X VM's, and a couple of SuperMicro Xeon boxes that host pretty much everything else.
It would seem that for decades I have apparently been under sway of an unfortunate misunderstanding. I genuinely believed that it was possible to issue a set of instructions to a computer in order, some sort of program you might say, which it would then carry out in sequence without further intervention on my part. This misunderstanding on my part is the only conceivable explanation for why during remediation the patches can't be pushed onto the host that the update server VM is on, after which a script on the vCenter Server appliance would halt the update server VM, execute the patches, reboot the host, take it out of maintenance mode, and then bring the update server VM back online. Instead you get to stupidly shut down your update server VM. Migrate it to another host, bring it back online, and then remediate its original host. This is totally not a massive waste of time.
Apparently that is insufficient punishment for the lowly Essentials user though, as updating the host that the vCenter Server appliance is running on is even worse. You can't easily migrate it, since you have to shut it down to do so, but then you no longer have the vCenter Server web client to work with so forget migrating the appliance. I leave it to the reader's imagination to decide which is the least pain inducing way to deal with this particular annoyance.
All this could easily be dealt with if they'd just at least give the Essentials license an entitlement for vMotion when the update manager is being used to remediate hosts. Instead, using the update manager almost certainly takes longer than doing everything manually.