Are there any plans to add this to paper-fab or paper-icon-button, or polymer proper? It would be great to have support for material design's 'delightful details', w/o having to code up custom solutions for each client.

In core-icons, the icons such as menu and arrow-back seem to have bolder lines than the ones in icon-transition. Is there anyway we can make the lines bolder for consistency?

Would be great if the icon could rotate when transitioning, as shown in some of the latest material design apps. Ex. in the Play app, the menu icon rotates 180 deg clockwise each time it switches between the hamburger menu and the back arrow.

I notice that this element is depended on version 0.5. And the APIs of Polymer 1.0+ have been changed.
I wonder if this element can be implemented into 1.0+ version.

It's really amazing. Hope it can be considered in version 1.0+ 👍