A minor update to Reveal Pro: 1.3.323 adds resources-{view,sticker} built on top of vega view that shows live chart with JVM's CPU and memory utilization. So far no docs update on the site since I want to add some more stuff to vega visualizations, but here is a screenshot:

A minor update (Free: 1.3.263, Pro: 1.3.325) adds support for listening to vega view signal updates using :on-signals prop. Still no official docs since there is more to do for vega, but here is an excerpt from vega-view docstring:

:on-signals    map from signal name to 1-arg fn that will be called with new
                   signal values (will be deserialized from json with
                   keyword keys)