The responsibility of the control is to present a paginated version of its content to the PrintDialog.PrintDocument method. The logic we have implemented does not have anything to do with the device used and will be executed in the same way for all printers. How WPF proceeds to print the paginated document is not something we have control over and apparently this is what slows down the printing to the printer you have mentioned.
If the problem were to be document-specific, we could have looked into the issue to see if it is related to the way we process the document. As this is not the case, unfortunately we cannot come up with any suggestions on how this issue can be solved.
All the best,
the Telerik team