DataGridExtensions | Modular extensions for the WPF DataGrid control | Grid library

EDIT: In order to clear up all confusions with instanct-closing as duplicates. Please see point (3.) explaining why the accepted answer does not apply. In short, the linked answer is fine as long as you are not using XAML to set the value because XAML will never call PropertyChangedCallback because it re-uses the default instance.

Question:
Considering a simple WPF's Attached Property of ObservableCollection type with XAML-defined value:

XAML:

I need to be able to run a command on MouseDoubleClick event inside my DataGrid, however it seems that the event never makes it to the Grid due to the cell editing function that is started on a single click, even though I have a read only grid.

Here is an answer that talks about overriding the edit function on a winforms data grid, but I can't find the same on a windows controls data grid.

MouseDoubleClick event is not fired when a cell is double-clicked in System.Windows.Forms.DataGrid

I am fine with doing away with edit all together, altough I would like to keep it if possible. I do need to add edit capability in at some point, but it will only be activated by clicking on an edit button on each row, so if I need to have edit overwritten somehow I can just make the button open an overlay that allows them to enter the row values rather than entering them directly into the grid.