Specifying properties using the presentation attributes

I create a plug for inkscape (https://launchpad.net/interink) which add interactivity (like quizz) to a svg document.
The plug copy some piece of svg from files where the style is defined by his attributes (ie with fill="#334455" and not style="fill:#334455").
But when it's copied (or to be more precise when it's move), the style is definied by inlineCSS (style="fill:#334455").
The problem with this is i can't add external stylesheet.

So i think inkscape would better used presentation-attributes style and not inlineCSS style.