Currently the list of marker is limited, but it isn't the case for the WPF RadChartView.
RadChartView permits the display of specifics points (like a vertical line for displaying a limit), but it isn't possible in report.
WPF DataTemplate would surely impossible to reuse in report, but some other custome template should be available like SVG, bitmap, or UTF-8 character (not the best customable solution, but it already increase a lot the possibilities)