Hi, static NAT ports for UDP are a godsend for real-time protocols. Anyone who has troubleshooted WebRTC knows this: they're worth their weight in gold. They cost nothing, except to acknowledge that port "randomization" in UDP is not a security feature.
pass out quick on igc0 inet proto udp from igc1:network nat-to (igc0) static-port
pass out on igc0 inet from igc1:network nat-to (igc0)
pass out quick on igc0 inet proto udp from igc1:network nat-to (igc0) static-port
pass out on igc0 inet from igc1:network nat-to (igc0)
"