Only the first selected item is returned in the AddedItems argument of the SelectionChanged event when using the Extended selection mode.

Currently, to modify the default appearance of the cells you can use the CellDecorationsNeeded event of RadVirtualGrid. The event args exposes a predefined set of properties that can be applied onto the cell. However, there is no text alignment.

Introduce a cell text alignment property in the event args similar to the CellTextAlignment of the RadVirtualGrid itself.

Currently the alternation brush takes precedence over the selection brush. Implement a way to change this behavior.

When the SelectedIndex is pinned, the selection is visually transferred to another row.

Scheduled for:
The fix for this issue will be available with LIB (version 2018.3.1302) scheduled for publishing on Wednesday, 2nd January 2019.

Scheduled for:
The fix for this issue will be available with LIB (version 2018.3.1302) scheduled for publishing on Wednesday, 2nd January 2019.

If you create a custom editor in the EditorNeeded event or method override, and don't set the editor's value, an exception is thrown.

Reproducible only with DataProvider.

To work this around set the custom editor's initial value to a value different than null. Or you can use the events instead of DataProvider.

It should have similar behavior to the one in RadGridView https://docs.telerik.com/devtools/wpf/controls/radgridview/columns/column-groups

UPDATE: The issue occurs in both cases - when populating with data manually and through DataProvider. We will be able to provide a fix for the DataProvider case, as well as the manual popupating if you use TextBox for editor. 
If populating manually and you need to use a different editor such as DateTimePicker for example, you will need to handle its background on creation. 

Available in LIB version 2017.3.1113, it will be also available in the R1 2018 Release.