In previous version of QGIS when using the print composer there was an option to have the map displayed as a rectangle, cached or render. This was particularly useful when the map showed lots of information and took a long time to load/redraw. I am setting up a template to auto generate a lot of maps using an atlas but can no longer find this option and it takes quite a while to render the map, even though i don't need to see it, just want to export it. Does anyone know if this feature has been removed completely, hidden somewhere else or will be implemented back in further versions?
It's been removed, as a result of the map items now rendering in a background thread. (Because the map renders in the background, it no longer causes the "hangs" while rendering, so even for complex maps you can continue to work within the layout designer while the map renders away in the background).