Add Two Scopes with Different Range in Same Subnet for Windows DHCP Server

The Microsoft DHCP server has no concept of a list of MAC addresses that are outside one of the configured DHCP scopes. I'm also not aware of any way to get the Microsoft DHCP server to return an IP address outside of the scope in which the DHCP relay agent's GIADDR address falls. I don't think you're going to be able to replicate what you had w/ the Microsoft DHCP Server.

As an aside: Before you consider handing-out IP addresses to public clients using a Microsoft DHCP server you may want to get a clear statement from Microsoft as to whether or not these devices need CALs. Microsoft has made contradictory statements about this. To be "safe" I always use a non-Microsoft DHCP server for public subnets.

Edit:

You're absolutely right that a DHCP superscope will allow IP addresses to be assigned to clients outside the subnet of the GIADDR that the relay agent passes. It's not a feature I've ever used in production but, even so, I feel like a bit of an ass for not thinking of it.

This is likely because WDS is installed and using port 67 on the same server.

You'll need to modify the settings of WDS to not use port 67, which can be accomplished with this command:

wdsutil /set-Server /UseDhcpPorts:No

https://support.microsoft.com/en-ca/kb/954410