I set up DNSMasq when I work at home with home networking equipment. a lot of the home issued stuff won’t have settings to be able to designated the tftp/boot server or the next-server. Using a DHCP proxy service like dnsmasq has prooved beneficial.
Something else I have done is turn the DNS portion of FOG on and use a hub and keep it separate from the network unless an internet connection is required, which I have not needed DURING imaging, only after.