I am the one that ask for this feature, and I don't know why we cannot have WPF PropertyGrid features the same as WinForm PropertyGrid:
The possibility to select the edit control or read only, in WPF PropertyGrid, before getting into cell editing, like it is possible (and I did) with WPF RadGridView (with GridViewBoundColumnBase class).
In some cases we have to decide if the property is read only or about the edit control according to the selected value of a different property.