Request rendering right from an http://openstreetmap.org/edit?...

It would be nice to request rendering 12-level tiles right from an edit page.
I mean the following: zoom in/out to see your changes on the screen, press a “Request render” button, view current tiles being requested to render and press “confirm”.
At the moment it is very complicated to do it.
Thank you!

Doesn’t it take lots of time for those to render, which mean you will probably have stopped editting when those tiles are rendered by Osmarender?