I can see this was raised before. Here is my suggestion. I understand building a function that would do a silent printing by accepting all the printer settings my be a big feature. So what am suggesting is just to add a function like PrintUsingDefaultPrinterSettings. I have done this code change manually and tested it on windows, I really have no idea how does cef gets compiled on linux on mac and not sure what would be the complexity there, but I am hoping it is as easy.
Referring to my comment here (viewtopic.php?f=6&t=12567#p47836), it shows how to change the code to just print using the default printer.