The NSI filter-driver interception is the standout move in this release and it's worth not skimming past. When the documented API (NotifyIpInterfaceChange with MibParameterNotification) doesn't fire for MTU changes, Microsoft confirms the bug in 2021, and the fix never ships, you either live with a 3-second polling loop or you attach a filter driver to \Device\Nsi using IoAttachDeviceToDeviceStack, reverse engineer IOCTL_NSI_SET_ALL_PARAMETERS, and pull MTU straight out of NSI_IP_INTERFACE_RW while the change is being dispatched. That's a very different level of Windows kernel work from 'port Linux WireGuard to another OS.' The NetAdapterCx-helper trick (NdisWdfGetAdapterContextFromAdapterHandle) that kills the Reserved-field ticking time bomb is the quieter fix but arguably more important for the next decade of reliability.