Our RadDomainDataSource just like the stock MS DomainDataSource uses the DomainContext for everything it does.
So you can take the DomainContext instance that you assigned to the RadDomainDataSource.DomainContext property and do the same thing with this DomainContext.
I suppose that if you "piggy-back" an additional entity back to the server it would not cause any harm.
Can you try this and see how it goes?
the Telerik team
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