I would like to have the DHCP option 006 (DNS servers) in the address reservation. 

This would solve a lot of problems for me: 

I have 3 DECO x55 with Guest network enabled with LAN access OFF 

When the DNS server is located INSIDE the LAN, the GUESTS can't access the DNS server

if i could change the DNS setting for all reserved address or vice versa, then i could give GUESTS a public DNS while all known clients will get the FIXED LAN DNS server IP.