... The ClientEditingEditViewModel has all the code for the preparing new rows, inserting, canuseradd etc. It seems like the code from this module for the methods and properties for an editable grid are just copied into each ViewModel that handles a grid rather than creating a generic ViewModel that handles all grids...

Yes, I agree that implementing such pattern, to create a generic ViewModel that handles generic on all grid, would be better than copied the methods and properties into each ViewModel.

Intersoft ClientUI MVVM Data Application (WPF) project template has implemented this pattern. It has EditableGridViewModelBase and EditableGridViewModelGenericBase (this class is located in [ProjectName]\ViewModels.Infrastructure). Hence, we can simply inherit from those classes and use it in our ViewModels, for example: ProductsViewModel.

Thanks again for your message. The ideas and suggestions of innovative, thinking people are always welcome.