You're right, 5ms updates aren't really any more useful than 20ms updates. Although for the current esolangs `React.memo` serves most 5ms use-cases, I'll be happy to implement fixed-rate updates or debouncing when a visualizer gets too complex for simple optimizations.
Theoretically, the visualizer window can show anything I think - as long as the required props support structured cloning[0], it's really just a React component. Performance is the only limit, but the above methods will help when that limit is reached. A Leaflet.js map for the Taxi[1] esolang will be interesting to implement, for example.
[0] https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers...