Different line stroke thickness on a single line (can set every node stroke thickness), for example on Paint Tool SAI, it will be very very helpfull for example to create character with more natural stroke, or creating a manga or an anime styled character.
Try the Artistic media Tool.
that's actually not the same thing i'm requesting, what i meant is to specify each node width on the same line, artistic media tool can only specify width based on the presets not on each node. try Paint Tool SAI on vector mode and u will see what i meant.