Given the following column that is bound to an int value(actually to a DataGridCollectionView first), how do I get the userInput to allow only digits to be input? On other controls in my app I've used the PreviewTextInput event (backed by a regex that handles any non-numeric input), but that does not seem to be available on the column definition ...

I have a new feature request for you.  I have swapped emails with your support department recently about columns with * widths not being resizable, and how this is a known limitation. When you assign a column a * width, the column will not allow the user to resize it.  Columns that do not have * widths are still resizeable, and a mix of ...