m0n0wall Forum - is there anyway to modify or replace dhcp server?

hello , i want to replace or modify the present dhcp server , i want to edit subnetmask provided to the clients and add more dhcp networks on same lan
i tried mikrotik before , what i liked in its dhcp server that it can give each client a subnet mask of 32 although the network mask was 16 so that option isolated all the network clients and that what i want , they didnt see eachother even over the hubs level and that decreases the arp spoof and any other problems in the network
is that possible in monowall by modifying in the image ( i found out that monowall dhcp server checks if the dhcpserver and client have the same mask and if not it wont give that client an ip)
or
can i replace the dhcp server with another one that does that??
thnx