Emit user activity data using a volatile socket event to prevent unnecessary buffering of non-critical data.

[mkahvi]

User Experience

For example player cursor position is not critical data, it shouldn't be transmitted as if it had to reach destination no matter what.

Ref: https://socket.io/docs/v3/emitting-events/#volatile-events

It's not quite as good as proper UDP, but it potentially removes some pointless network traffic.

I unfortunately didn't spot any other message types that would benefit from this, but even using it for cursor can help people with flaky connection not having to constantly buffer more and more.

[aaclayton]

Good suggestion and an easy improvement.