Hi,

It would be a good addition to the Gantt component if a progress completion indicator is rendered on the tasks as in Kendo UI for jQuery.

Provide the ability to change a task duration by dragging and dropping it at the required position. 

Similar to the Kendo jQuery Gantt:

https://demos.telerik.com/kendo-ui/gantt/index

and Gantt Chart from Syncfusion.