This was partially discussed in RT-36140.
In that case, dragging a table column's resize grip changes the cursor during the drag as the column is not resized immediately but during the next layout pass. This means the cursor might get out of the grip before the layout pass happens.
Fixing the cursor at drag might solve this issue and other similar issues.
But this might affect other areas as well like press-drag-release (see HelloWorld sample, HelloFullPDR), which could be modified (and it would be reasonable to do so) in a way that the cursor changes based on the current area under the Node. So in case of PDR is initiated, we should probably allow cursor changes.
Also drag & drop functionality must be considered and tested afterwards.