The current node.js tw server lets the clients “poll” for updates, but the polling-period is 1 minute (https://tiddlywiki.com/#Hidden%20Setting%3A%20Sync%20Polling%20Interval). You could set that very low (5 seconds or so), and then reset it when you are done… leaving it low would burn lots of resources as you would be sendging an http request every 5 seconds, and most of the responses would be empty.
See my new thread on realtime multi-user multi-wiki syncing for an, admitted, teaser. But this functionality is coming soon.