Yeah I noticed with time nmap with unicast, mine all need about 3.5 seconds to respond.
A very sleek feature especially bc the own host gets reported as well which nmap doesnt do when broadcasting.
Troubleshooting DHCP has gotten allot easier.
Amazing job !
pi@ph5:~ $ pihole-FTL dhcp-discover
Scanning all your interfaces for DHCP servers
Timeout: 10 seconds
* Received 303 bytes from eth0:10.0.0.4
Offered IP address: 10.0.0.195
Server IP address: 10.0.0.4
Relay-agent IP address: N/A
DHCP options:
Message type: DHCPOFFER
Server identification: 10.0.0.4
Lease time:1d (86400 seconds)
Renewal time:12h (43200 seconds)
Rebinding time:21h (75600 seconds)
Subnet mask: 255.255.255.0
Broadcast address: 10.0.0.255
DNS server 1: 10.0.0.4
Domain name: "dehakkelaar.nl"
Router 1: 10.0.0.1
--- end of options ---
* Received 303 bytes from eth0:10.0.0.2
Offered IP address: 10.0.0.109
Server IP address: 10.0.0.2
Relay-agent IP address: N/A
DHCP options:
Message type: DHCPOFFER
Server identification: 10.0.0.2
Lease time:1d (86400 seconds)
Renewal time:12h (43200 seconds)
Rebinding time:21h (75600 seconds)
Subnet mask: 255.255.255.0
Broadcast address: 10.0.0.255
DNS server 1: 10.0.0.2
Domain name: "dehakkelaar.nl"
Router 1: 10.0.0.1
--- end of options ---
* Received 312 bytes from eth0:10.0.0.1
Offered IP address: 10.0.0.109
Server IP address: 10.0.0.1
Relay-agent IP address: N/A
DHCP options:
Message type: DHCPOFFER
Server identification: 10.0.0.1
Lease time:1d (86400 seconds)
Renewal time:12h (43200 seconds)
Rebinding time:21h (75600 seconds)
Subnet mask: 255.255.255.0
Broadcast address: 10.0.0.255
DNS server 1: 10.0.0.1
WPAD server: "
"
NetBIOS name server 1: 10.0.0.1
Domain name: "dehakkelaar.nl"
Router 1: 10.0.0.1
--- end of options ---
Ps. those 44 & 252 options are coming from the Asus router which I dont use ... who needs NETBIOS 
EDIT: maybe reporting the IP three times is a bit redundant:
* Received 303 bytes from eth0:10.0.0.2
Server IP address: 10.0.0.2
Server identification: 10.0.0.2
Maybe drop the second line ?