text-decoration

Hi SVG WG,

How does text-decoration work in non-trivial cases? For instance:

What happens with text on a path? Is the underline a continuous curve or a
set of discrete straight lines under each glyph?
What happens with text where the x, y, dx and or dy location is specified
for each glyph? What would the underline look like if each glyph within the
text was located randomly?
What does it look like if alignment-baseline is defined differently on
different tspan's within a text element?
What happens if each glyph is rotated differently within the text?
What happens if the writing-mode is set to tb?
How does it interact with glyph-orientation-vertical?
If the author uses SVG fonts and colours each glyph in the font differently
does the text-decoration reflect the glyph colours or the overall text
fill/style?

Thanks

Robert