Change height of droppable area if draggable is too small

[RinatRezyapov]

When I drag divider element which has small height I would like to increase height of area where I want to drop that element. Right now the drop area too narrow and people with touch pads experience problems.
I believe this problem is related to #981 in terms of onBeforeDragStart handler, but maybe, for my particular case, there is a simple solution?

[alexreardon]

Right now this is not supported. This seems to be similar to #930 so we can track it there