Request multiple IP-addresses via DHCP on a single physical interface (OpenBSD)

On OpenBSD, is it possible to request multiple IP-addresses via DHCP on a single physical interface? It looks like DHCP leased addresses can't be assigned as aliases. I though of creating a virtual interface and forward traffic to the physical interface, then run dhclient on the virtual interface (it doesn't matter if the second address is assigned to a virtual interface and not as an alias to the physical interface). Unfortunately I wasn't able to get it to work like that.

Any suggestions? How would you do it?

DHCP requests are tied to MAC addresses, so normally a single interface can only request a single IP. I would see if you could get OpenBSD to create two subinterfaces each with their own MAC addresses and DHCP requests. Other option is to create a VLAN trunk so you can request a DHCP address in separate VLANs.