Low performance to load a svg file with many <use>

Hello,

I have a svg file with a high number of <use> and it takes a long time to load that document.

So, when I analyse where the time is lost, I see that the importNode() and the events handler in the buildCompositeGraphicsNode() function in SVGUseElementBridge class  are the most consumer of time.

For the events handler, it is the dispatchEvent() and fireEventListeners() in EventSupport class where time is lost, a high number of call is made.

If anybody have an idea to improve the performance, his help will be very appreciate.

Thank you very much.

Jeremie.