I had read a couple of books both of which said the sandwich technique is an out-of-date way of delivering bad news and it's significantly better to do it immediately to help not continue to build up to the bad news that the person on the other side knows it coming (because, let's face it, the sandwich is obvious from 100ft away).

Unfortunately I can't figure out what books I read and I'm having a hard time finding studies (just keep finding damn buzzfeed like article about using the sandwich). If someone else finds these sources or debunks them I would be greatly appreciated :)