In terms of speed, v9.2 for this program is actually a bit slower than v9.0 and v9.1. So apologies

And thanks to Janez for the post which prompted me investigate this further.
In terms of speed, plotting 10000 points takes around 1s for v9.0 and 1.4s for v9.2. V9.1 is actually faster than both at plotting, but is very unstable when plotting without pausing and crashes often.
In terms of stability, v9.0 crashes occasionally (especially if the panel is moved or interacted with by the mouse), v9.1 crashes within minutes of running, but v9.2 has not crashed for me so far (after hours of experimentation).
PC resource use is much improved in v9.2. CPU usage is slightly lower and memory usage is much lower than v9.0, although GPU usage is higher:
So in summary, the XY chart in V9.2 is not necessarily faster but it is much more stable and less resource-intensive.
And my original reply does stand. There are better dedicated graphing applications and Flowcode's graphing capabilities are only a small part its functionality.