SVG is completely unsuitable for recording pen stroke data, and fairly unsuitable as a publishing format for handwriting. It’s capable of representing a technic

SVG is completely unsuitable for recording pen stroke data, and fairly unsuitable as a publishing format for handwriting. It’s capable of representing a technical pen/fineliner with opaque, constant-width stroke tolerably well, but nothing else. For all other pen styles, you need variable stroke width (for which you have to switch to using a filled instead of stroked path, bloating it hugely and making it essentially uneditable), and also want some degree of variable opacity and/or texturing of the stroke (both impossible in SVG).