[MartinH]

Regarding the smoothing, I had assumed the method of rendering the line would be simpler while drawing, since it's continually refreshed, than after it's finished (when you lift the stylus) so I wasn't too surprised that things moved a bit. 

I'm not an expert in bezier curves, but I think the line does not necessarily pass through the points:

So even if there's a point at the peak of the letter I'm drawing, it could get smoothed out once the line is rendered as a bezier. Could it be that on some tablets, there are fewer points so more of the peak is being smoothed down? I find that my Surface Go 2 doesn't quite have the responsiveness of a Surface Pro, and maybe the rate of drawing new points is less.