Please support multicast for cameras

Please support multicast for less traffic for many cameras

???

Multicast is for one sender to one or many receivers.
The use case you describe is one or many cameras (senders) to one or many HA clients (receivers).
The number of cameras are not really important here.

Besides that camera feeds are usually just embedded iframes, so not something HA can change much,

Previously, TV set-top boxes worked using the multicast protocol. It’s sad that it requires video transcoding. But maybe you can get by with just video encapsulation?

Set-top boxes are one sender to multiple receivers.
That is still not the use case you have.