Useful things
An off switch for certain render types. Example. I accidentally start rendering in viewpoint there is absolutely no reason not to have a means of stopping it. This program does not have an autosave so there have been a few instances where a lot of work has been lost due to me not having the time to wait for a viewpoint to render 3000 frames. As far as I can tell this has been asked for multiple times and I get that there would be work involved but, as an animator, let me just say that sometimes you have to put the asset making fun stuff aside and work on the not so fun stuff like giving us a cancel button.
Let us go back to autosave for a second. I just noticed, as I was typing, that my complaint was autosaved. Really? Auto save on the forums but the program does not? LOL. It just saved it again. As I have been composing this it has saved no less than 3 times already. Comeon Daz.
Comments
Renders can be cancelled, the data upload to the render engine cannot (because, I believe, in geernal that would have a significant impact on performance in a process that is usually quick and perhaps doesn't have natural breakpoints). Animations cannot be rendered to the Viewport anyway, or do you mean playback with the Iray DrawStyle active? In the latter case you should simply be able to select another Drawstyle (try hitting cmd(Mac)/ctrl(Win) 9 to switch to Texture Shaded).
Autosaving text on the forum is quick, auto-saving a scene before rendering is not. In any event I'm pretty sure there are scripts which wills ave before starting a render, which can be bound to the cmd/ctrl R shortcut and given a button on the toolbar.