Couple of things you may want to add on your guide to reflect some changes on the latest UDM Pro firmwares;
IGMP Snooping tickbox must be enabled on your IPTV Vlan or you'll get the 15 second issue.
Auto-starting of the igmpproxy is busted because of some bug on the UDM Boot Script. After following the UDM Boot instructions, you have to drop into "unifi-os shell" and run "systemctl enable udm-boot". Then it'll properly work whenever the UDM Pro restarts.
Couple of things you may want to add on your guide to reflect some changes on the latest UDM Pro firmwares;
IGMP Snooping tickbox must be enabled on your IPTV Vlan or you'll get the 15 second issue.
Auto-starting of the igmpproxy is busted because of some bug on the UDM Boot Script. After following the UDM Boot instructions, you have to drop into "unifi-os shell" and run "systemctl enable udm-boot". Then it'll properly work whenever the UDM Pro restarts.