Block contextual menu should be available immediately when dragged to dashboard canvas area

It's hard to describe exact interaction, here's the short screencast:

http://screenr.com/Sh2

Basically, block contextual menu only apperars when "Done" is clicked. It this by design or is it some kind of JS-magic incompatibility what does not allow live rendering of contextual links? (note that actual block contents can be rendered live with no problem in dashboard canvas)

I'd recommend to render those links live.