Null value support for Chart for Xamarin Forms, so that if there is a null value, a line chart should appear "disconnected" at the point where the nulls are. Available in the R3 2018 SP release.
Currently, depending on the platform, the first piece of the pie is drawn at 3 or 9 o'clock. It should be possible for the developer to set the starting point to be 12 o'clock.
Allow easy exporting of a chart to a Xamarin.Forms image object. This will allow the images to be shared using social media.
When the chart has a lot of data, you may not necessarily want to show it all when the chart initially appears, but you may want to show the chart in a semi-zoomed state. Therefore, there should be properties which govern the ranges by which the chart should appear zoomed initially. So, the end-user should be able to zoom in/out starting from this state and then return to the same state if necessary (avoiding getting the whole data if he zooms out too much).