For example, can you make a Gantt chart with a single graph, such as running (green) and stopping (red)?
I carry this idea in my mind for about the month and still not started to do it. There is couple of complicated things I need to sort out. Problem I want to avoid is to give users widget which kills browser performance like chart node is able to do. (after long running too many data-points to calculate and render) But in same time the limitation should not be that much restrictive that most of people cant adjust it by their needs.
So, idea exists but nothing yet to show.
meanwhile you may find https://flows.nodered.org/node/node-red-node-ui-vega useful for it. Not tried for grantt but it is wery powerful.
Nice. I've seen that as a plug-in for Grafana some time ago.