Text "extent" in SVG 2 vs CSS Writing Modes

In reading through the CSS Writing Modes spec [1] (which is officially at
CR level), I discovered that it uses the word "extent" in a conflicting
sense to how it is used in SVG 2.

In the CSS spec, the extent of a text block is its the distance across
multiple lines.  In SVG 2, the extent attribute would describe the maximum
length of a single line -- something that the CSS spec calls the "measure".

The minutes from the F2F that chose the word `extent` aren't terribly
informative [2]: does anyone remember why this particular term was chosen?
If it was intended to synchronize with the CSS terminology, then we got it
wrong.  If its just an unfortunate coincidence, I wonder if it is not too
late to replace it with `line-length` or something else?

Amelia BR

[1]: http://www.w3.org/TR/css3-writing-modes/#abstract-dimensions
[2]: https://lists.w3.org/Archives/Public/www-svg/2015Feb/0033.html