Does macOS support AnyIP? I would like to assign a complete block to my Mac as described in this question: Can I bind a (large) block of addresses to an interface?

There it is explained that AnyIP is supported for IPv6 by the Linux Kernel and how to configure it on your device, but the command being used is ip, which seems not available on macOS. If this technique is supported on macOS, what is the command to achieve the same?

PS. I know how to add a single IPv6 to an interface using the command ifconfig -r -L en1 inet6 fe80::2/64 alias
The feature is not supported on macOS.

Depending on how many IP addresses you want to listen to, you could use a simple script to bind each IP-address to the interface individually using the ifconfig alias command.