Drawing Points In A Specified Z Order Across Series

I have a scatterplot with different series of points and I need to figure out a way to draw each point separately in a different Z order. This will acheive “layering” of the points based on some metadata criteria.

The main issue to solve here is as follows. Each series can have “highlighted” points (outlined in blue on the chart, uses SciChart point selection) and “selected” points (denoted by a star point marker) which are tied to a selection in a grid. Any point in any of the series can be Highlighted and/or Selected. I need the the non-selected and non-highlighted points to be drawn first, then the selected points, then the highlighted points. This would guarantee that the highlighted points are always drawn on top of all others, and the selected points drawn on top of all but the highlighted.

My attempt has been to create a custom chart modifier and override OnParentSurfaceRendered. In that method I build dictionaries of points based on the metadata grouping criteria, then start with the lowest Z index group (the non-highlighted and non-selected points) draw those points, and continue up to the highest Z order group (the highlighted points).

Is there a simpler way to achieve this point layering functionality across data series?

Thanks.