You can create, read, update, and delete each feature on its own.
Looking at the code I realized that dynamic changes to the data/datasets is indeed supported and will cause the chart to update.
BUT, no other change to a chart is being supported, eg.
We just launched the Datasets API, a new way to interact with custom geo data.
Speaking raw Geo JSON, the Datasets API provides an endpoint for every single feature.
In contrast to the Uploads API, which optimizes and strips uploaded data to make small, fast vector tiles, the Datasets API stores features up to six decimal points of precision.