While we still wait for a full featured ChartDirector with retina support, we got an interim solution:
I added a property CDBaseChartMBS.ScaleFactor which you can set to 1, 2 or higher to scale charts.
All values passed to the plugin are multiplied/divided by scale factor, so the resulting chart is bigger and looks sharper on Retina displays.
Especially as Xojo 2016r1 comes soon with retina support.
Please test soon with next prerelease and tell me if I forgot to scale a property.