Fill and stroke on paragraphs

fill and stroke applied to text

Gradients applied to different kind of text:

1) text with span: gradient fits to different line height

2) text with span: gradient takes the bounding box of the line

3) Gradient applied on paragraph: takes the bounding box of paragraph

4) Gradient applied on paragraph: takes the individual line height

SVG 1.1 does 2) and 3).

What is desirable for HTML paragraphs? Add new keyword beside objectBoundingBox, userSpaneOnUse? Something like lineDimension or orientation dependent lineHeight?