https://platform.uno/ has just reached version 2.0, please add support for using UI for UWP in an Uno project.

creation of a line graph on a scatter point chart with gaps in the line when expected values are missing 

Something like this:

Currently the only way to apply different colors to the bars is through the ChartPalette. Provide an option to set the color according to the bound data item.  

when applying the filter in a column where the scroll is on the right, all the scroll is reset to the left and the popup moves to another column. 

Data can come dynamically from JSON, XML, and SQL.  Without the ability to bind a grid to commonly used structures (like a Newtonsoft JSON, .NET DataTable or Dictionary), this grid has VERY limited use for apps that use modern ways of gathering and managing data (like JSON-Schema).

When you are in tablet mode and try to type 6 from the on-screen keyboard - the "-" sign is applied. 

Provide a tabstrip control that allows users to display content on tabs.

 - Tab content could use virtualization to avoid extra rendering
 - Follow themes from Telerik
 

Provide component that is able to read and decode codes from image.

Universal barcode.

Make the gauges universal.

When the RadNumericBox has focus it displays a clear button on the right, the "X".  In a high data density screen or grid, space can be at a premium and this button takes space, and when the user has a keyboard is not necessary (they can use the delete key) It would be space saving if this button was optional (as per the WPF version).

Universal combo box.

As per the title.  The current controls lack a fully virtualised, high performance combobox/dropdownlist.

Add a setter for the AutoCompleteBox's SelectedItem property.

For example, to use different keys than the default arrow keys to switch from day -> month -> year in DatePicker

Enable drag and drop between cells of different rows in the DataGrid for UWP. Or a way we can develop it ourselfs.

Provide ability to control buffer size in order to load more items outside viewport.