SpritePointMarker on FastBubbleRenderableSeries, sprites are upside down and backwards

Having some weirdness when rendering a sprite as the points on a FastBubbleRenderableSeries. For one, strokethickness, stroke, etc don’t seem to do anything, and furthermore, the sprites are rendered upside down and backwards. If I set the sizes (zvalues on the xyzdataseries) to a negative number, the sprites are only mirrored around the y-axis.

However if I instead use the same sprites on a XyScatterRenderableSeries they look like expected. I would just do this but I need per-point scaling (and hopefully I can figure out how to do per-point hover outlines and tooltips as well)

Originally I had been using an ugly hack of embedding the PNG into a custom svg annotation, but the performance was terrible after a few dozen points were on the chart at once.