It would be hugely beneficial to enable DHCP in ‘listening’ mode only, so server can discover the names attached to MAC addresses in DHCPDISCOVER. It is known feature for some enterprise networking products called DHCP fingerprinting. As DHCPDISCOVER broadcast packet contains OS information as well. (Where another pie-chart for OSes could be later added)
This will save the folks with home routers that does not allow disabling DHCP, or simply don’t want to change their existing DHCP settings.
This request is the same as Passively Discover Hostnames through DHCP but it was closed long ago without clear explanation.
It was closed due to 6 months of inactivity.
Scroll that page down. After the last post you will see the reason:
I fully aware of that!
I meant it was left without further comment, neither dropped nor planned.
I think you need to submit this to the developer of DNSmasqd in order for FTLDNS to support it ?!
However…
IMHO you simply always need to have your own Router in order to benefit from Pi-Hole without having to jump through all kinds of hoops all the time 
- OPNsense/OpenWRT/pfSense/DIY nftables + everything else in a random Linux distro/etc.
- A nice and simple DrayTek Router in case you are on a xDSL connection.
And if you are not on a Fiber or xDSL connection then ask your Cable ISP to put their Router in Bridged Mode and then add your own Router after theirs 
