It would be nice to have an event fired ìwhen the user places the mouse over a boundary between two items.
The event could be used to let the user change the quantities of the items (with the mouse) without changing the total value.
For example you can imagine a disk, and let the user change the partition size just dragging the boundary of iterms.
We have implemented this on capacity item level where you can set AllowChange property to True to change the value of an item. The OnItemChangeValue event is triggered for further finetuning.
This feature was implemented.