From the Qt QTabBar docs, this looks interesting:
Code:
changeCurrentOnDrag : bool
If true, then the current tab is automatically changed when dragging over the tabbar.
Note: You should also set acceptDrops property to true to make this feature work.
By default, this property is false.
This property was introduced in Qt 5.4.
Access functions:
bool changeCurrentOnDrag() const
void setChangeCurrentOnDrag(bool change)
So if you start to drag a non-current tab, it will make it the current tab automoatically. Not sure if this will help but it would be an easy change to make and test. If so, we should be good to go.