I did consider such cases. My current theory is that it is unlikely that clients will keep up a torrent of updates so constant that there'll be a lag of more th

I did consider such cases. My current theory is that it is unlikely that clients will keep up a torrent of updates so constant that there'll be a lag of more than, say, a second before any given change gets through. But if this would turn out to be an issue, you could have the server implement some kind of fairness algorithm by slightly delaying clients that recently got their changes through and prioritizing those that made a few unsuccessful tries.