Currently, the RadTaskBoard control does not have dedicated keyboard navigation support. We could introduce support for it.

Improve the automation logic to increase its readability by accessibility tools.

Introduce an option that allows the user to reorder the columns via drag&drop.

In scenarios where the RadTaskBoard's TaskBoardColumnsPanel scrolling is disabled, the panel's calculated height leads to the RadTaskBoardItems being cut off. The panel should instead stretch vertically to display all its child items.

Currently, the card model is added to a group when initially added to the ItemsSource of RadTaskBoard. Also, it can be moved to another group by drag/dropping on it. However, if you update the card model property that is assigned to the GroupMemberPath of RadTaskBoard, then the card is not moved to the corresponding group in the UI.

To work this around, remove the card object from the ItemsSource, update the group property and then add the card object back in the ItemsSource.

The TaskBoard card could expose index property, which will hold its position in the column.

When the theme is changed runtime in the NoXAML scenario, the control is not visible anymore.

Create an API to customize the DragDrop behavior.

At the moment all Tags are just objects and presented as Text only. It would be nice to display an icon besides the text and modify the color of the tags also. Maybe a "TagModel" in analogy to "TaskBoardCardModel" would be a solution with properties like "Icon", "Color", "Text".

The Height property of the RadTaskBoardItem is not respected when setting to a different value thus preventing us to have items with different height.

When placed in TabControl, for example, and the TabItem with the TaskBoard is deselected (leading to the control being unloaded), the items are cleared when the TabItem is selected again. 

Currently, the width of the category indicator for each item is a fixed size, depending on the design of each theme. Include an API for changing this value.

Add built-in editing support for the tasks in RadTaskBoard.

The new button should be placed in the column container under the tasks/cards and it should add a new task.

This feature is the same as the "Add a card" button in RadTaskBoard for WinForms.
https://docs.telerik.com/devtools/winforms/controls/task-board/task-board-adding-task-cards