We've been doing 443 port sharing with BLAST for some time now on UAG. I just recently noticed that even when the Blast External URL is set to <hostname>:443, it appears that 8443 is still in use for UDP. TCP is being used on 443 correctly.
I've tested this on both UAG 3.3.1 and 3.7 on Horizon 7.10. I opened a ticket with VMware on this and they essentially said to configure 8443 on the load balancer/firewall as a workaround.
According to this, UDP 443 can also be used to access a desktop through the UDP tunnel server. The port configuration is set through the Blast External URL property.
But the table specifically says if you configure 443, then 8443 is used for UDP. Does a forwarding rule of some sort need to be used for UDP-443 to be utilized? Trying to figure out if this is an undocumented bug or expected behavior.