Hey there, thanks so much for this example - agreed that some things aren't well explained. I’ve been applying this to my own project and am successfully applying signals from external elements to update a value inside a Vega spec. But I’m struggling trying to get it to update a filter transform or condition test. Do you know if that’s possible? Any insight you're able to share will be super helpful. (An oversimplification, but the use case is to have external elements update a highlighted line in a line chart with several series)