Wow, started reading this now.

There's a lot of surprises in there for sure. The people crafting the spec seem to have had some peculiar goals that I don't quite understand. Especially all the implicit stuff in path data is surprising to me.

Also, a relative value of stroke-with is "relative to the diagonal length of the current viewbox". This was surprising, but makes a lot of sense when I think about it. And the default unit is %, which also makes sense after some thinking.

Seems like frustrating work, I'm glad the author can channel it into writing :)

Thanks for sharing.