Hey there,
I know this is not a new request but I couldn't find any issue related to this topic nor any mention in the future proposal for the specs (#StrokeProperties) but if I'm wrong feel free to close this issue :)

I was wondering if a stroke alignement property could be part of the future specs?
Taking Adobe Illustrator as an example, it allows three type of alignement (Center, Inside, Outside) but when exporting to SVG using inside and outside values will convert the path using a stroke into a plain path.

Open path

I also noticed that Illustrator doesn't allow an alignment if a path isn't closed.

I guess the reason is linked to the naming of the alignements since an open path doesn't have an inside or outside part.
But maybe the outside could be defined based on the clockwise direction of the path?
(Using different naming could also be needed)

Thanks!