To scale to thousands (is this even useful?) of e2e users build a tree of participants who can remix each other's video. Pick a handy mixing ratio like 4:1 or

To scale to thousands (is this even useful?) of e2e users build a tree of participants who can remix each other's video. Pick a handy mixing ratio like 4:1 or 9:1 (a square helps, since they compose nicely if downscaled to a grid vs. active talker stays fullscreen) and nodes with the highest bandwidth and lowest latency take M-1 streams and add it to their own to make an M:1 mix which can be forwarded to a node closer to the root which produces another M:1 stream, and the root sends a single mixed stream down the tree until every participant has the mix. Max bandwidth at each node is M down and M up. Minimal spanning tree with max M edges per node recomputed as participants leave and join. Build 3 or 4 distinct trees and leave the connections open for more rapid switching if intermediate nodes stop participating.