here a wish for something what can't be done at the real world, but could be possible at Enscape - adjusting the focus range by keeping the max blur. Often I like the nice DOF blur in the near and far away, but the focused range looks to small. Ideally the focus slider could be splitted into two sliders - one for start and one for the end of the focused range, but a focus depth expander option could be good too, since it would work with a simple "focus target by camera" (I hope it comes soon ).
Since the DOF effect is a post effect this could be done by a flattened range of the z-depth like at the screenshot. I used this technic for post work DOF some times in the past.