[Inkscape-devel] Add to a blueprint?

How can I add comments to this blueprint at launchpad:

https://blueprints.launchpad.net/inkscape/+spec/richer-extension-parameters

I wanted to add a suggestion for an angle selector widget, like the one proposed for GIMP here:

http://gimp-brainstorm.blogspot.com/2007/12/angle-widget-for-motion-blur.htm...

-Rob A>