Most likely you want some system to be unable to route traffic to other networks, e.g. internet.
You can solve that in another way. When you click on its lease you can make it static, and you
can add a filter in the router that blocks this specific address in the forward chain.
That should have the same result....
Unfortunately it's not the solution of my problem. I use OpenVPN and I don't want to give my users admin privileges (OpenVPN's way of route pushing requires it), that's why I configure remote network card using DHCP. I mean settings like suffix, route pushing etc. I don't want any default gateway for one reason, I cannot configure its metric. Funny things happen when Windows choses VPN gateway instead LAN one.
In DHCPd it's simple as f*** (sorry), same with pfsense. Ability to control host configuration based on lease in such case is important...