Just a followup for anyone that got here from a google search:
UniFi will now resolve hostnames for my primary network as desired:
user@host:~$ nslookup monitoring.lan.lol 192.168.1.1
Server: 192.168.1.1
Address: 192.168.1.1#53
Name: monitoring.lan.lol
Address: 192.168.1.230
But no joy when I ask it to resolve my VLAN network (even when I specify 192.168.11.1 as the DNS resolver).
user@host:~$ nslookup monitoring.storage.lan.lol 192.168.1.1
Server: 192.168.1.1
Address: 192.168.1.1#53
** server can't find monitoring.storage.lan.lol: NXDOMAIN
Setting the domain on the storage network/VLAN forced resolution to where I want it which is good-enough for my needs, but if you need DNS resolution for both networks, search on!