Yes, you can set options based on conditional statements in the ISC dhcpd server. Specifically you can test if the dhcp-client-identifier option is present in the incoming DHCP packet, and if it is set the option for the response packet to the incoming value by this expression:
# other options in scope ...
if exists dhcp-client-identifier {
option dhcp-client-identifier = option dhcp-client-identifier;
}
# other options in scope ...
The left side of the = sets the server parameter name, the right side data expression will return the contents of the parameter name from the client packet.
For more info see man dhcp-eval and the SETTING PARAMETER VALUES USING EXPRESSIONS section at the bottom of man dhcp.conf