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.
The VisibleRange property can hold the actual visible minimum and maximum of the axis while the chart is being zoomed and panned.
Currently the only way to apply different colors to the bars is through the ChartPalette. Provide an option to set the color according to the bound data item.
In some cases, a redundant extra tick is drawn when using a DateTimeContinuousAxis.
When you have a Chart with PieSeries and enable the SelectionBehavior - selecting a specific value makes it split from the pie chart and stand out. We should consider exposing another state, where the integrity of the pie chart is not broken and the selected items are just highlighted or probably have a bold border, etc.
If series' ItemsSource is a collection of objects implementing INotifyPropertyChanged, the chart should be automatically updated when an item is updated.