Hi
Build 2016-04-23 2, if region render has been used, VFB history shows on preview full picture, but actually stores only this region. Doesn't matter which region has been used Corona's or native. In attachment there are screenshot, picture saved from history and picture saved saved from current VFB - it saves whol picture, as it should be done
3DS Max 2014
P.S. the same thing with native VFB update as 2 posts above