Currently, when you scroll the RadGridView control the "click here to add new row" button goes out of the viewport. Allow to pin the button, so it float at the top or bottom of the viewport and to be always visible.

Provide option to set if the grouping is case-sensitive

Convert the Mask property of GridViewMaskedInputColumn to a DependencyProperty in order to be bindable.

Special chars '+', '-'. '""  modify the default search criteria in the search as you type feature.

https://docs.telerik.com/devtools/wpf/controls/radgridview/features/search-as-you-type#modifying-the-searching-criteria

Add option to disable this behavior. It would be useful in scenarios with strings starting with + or -.
Also option should be available for setting in MultiColumnComboBox.

For example, an event that will occur when the filter icon is clicked or when the filtering drop-down is opening/closing.

Currently, you can set the data format string of the cells in a GridView column by using the DataFormatString property of the column.

Add a mechanism to select the DataFormatString per cell. For example, this can be done using the CellStyleSelector and a new property in the GridViewCell. Or by introducing DataFormatStringSelector property.

Similar to the one in RadPivotGrid:
https://docs.telerik.com/devtools/wpf/controls/radpivotgrid/features/localdatasourceprovider/serialization

And here is an online demo:
https://demos.telerik.com/silverlight/#PivotGrid/Serialization

Currently, you can use only the predefined one - IsEqual, IsNotEqual, etc. Add an option to create operators that execute custom filtering action. Also, add support for modifying the default operators.

Currently VQCV caches all the items once they are loaded. In this way the data virtaulization functions only through the first bottom-most item scrolling. The idea behind this item is to make this behavior optional by introducing an alternative mode.

Currently, if the value set to the RowHeight of RadGridView is lower than the Height of the highest cell(or the Height of a Hierarchy defined), it will not be respected. Provide an option the RowHeight to have greater weight than the height of the cell.

I would like to be bale to modify at once several cells of a GridViewComboBoxColumn, when using the common ItemsSourceBinding for all rows (in my GridView, the selection ​is: SelectionMode="Multiple" SelectionUnit="FullRow").
So I would like for the selected rows to apply the same value as the edited cell.

Will be nice to have this feature. I have a solution from support by replacing " with *. But it's the way search should work. Click on link and go to Wildcard *: Searching for Unknown Strings section.
https://www.howtogeek.com/school/learning-windows-search/lesson4/

GridViewCell.Errors - System.Collections.IEnumerable Errors { set; get; }

Errors collection always returns a collection of strings.  When using .NET 4.5 and INotifyDataErrorInfo the errors can be any type. In our case we are using a custom ValidationResult object that has different severity levels.

Because GridViewCell.Errors always returns strings and not the original underlying ValidationResult object our DataTemplate for ValidationResult is not applied.

You can not select different filtering options through keyboard navigation. The only possible way to select a filtering operator from the list with available filtering operators is to click on it.

Implement Excel-like horizontal locked scrolling. Clicking on the scrollbar should scroll into view the first column that is not visible at the moment, i.e. all visible columns should be moved out of the viewport.

Respect IVirtualizedItemProvider for items of RadGridView .