Yes and yes.
Its below dnsmasq directive that needs to be added:
$ man dnsmasq
[..]
-O, --dhcp-option=[tag:<tag>,[tag:<tag>,]][encap:<opt>,][vi-en‐
cap:<enterprise>,][vendor:[<vendor-class>],][<opt>|option:<opt-
name>|option6:<opt>|option6:<opt-name>],[<value>[,<value>]]
Specify different or extra options to DHCP clients.
Full man page below:
With below DHCP server option:
$ pihole-FTL --list-dhcp4
Known DHCP options:
[..]
120 sip-server
121 classless-static-route
125 vendor-id-encap
Last time I checked, if want to push a static route, you also have to push the default route/gateway via this option.
Suppose my Internet router sits at 10.0.0.1, and I want to push a static route to 192.168.1.0/24 via 10.0.0.254, that directive would need to look like below:
dhcp-option=option:classless-static-route,0.0.0.0/0,10.0.0.1,192.168.1.0/24,10.0.0.254
You can enter that via the webGUI Expert --> All settings --> Miscellaneous below:
And oc a client would first need to renew its DHCP lease for the new route to propagate.