It's just a program to visualize svg. It builds a content tree using contributor objects, so documentation nodes can be gathered from different sources. The problem I saw with Yelp or any other html based browser was precisely that current Inkscape documentation is written with all the richness of svg that it supports. And the problem I saw with a pure svg browser is that you can't link to other documents, not without support from the svg rendering widget. Of course, let the svg implementation in mozilla be more complete, it could be used, but just try lo load a tutorial on it and see what happens. Then it comes a fast solution, the litle box at the bottom with the links for the in-presentation document.
No, I think there is no need to change the xsl stylesheet, as far as the program just renders svg. It's even possible to move xsl processing to the program.