Why don't simply (human) tournaments post their live PGNs directly on the web page? They're small, static files; why do you care whether 200 people poll them instead of 20?
In that vein, why is state of the art still “poll this PGN, which may or may not be complete, every second to see if anything changed”, even for blitz? Long-poll is a thing. WebSockets is a thing. PubSub is a thing.
I'd love to actually do something about #2, but without knowing a large group of relevant tournament directors, it doesn't actually do any good