I'm finding that the opposite is true. The more time I spend proofing the better off my output is. Wasting darkroom time on inferior negatives is a problem. Often I will have an entire roll of a single portrait session. Which of the similar expressions is the one worth spending an hour printing? It's not economical to answer that question by spending 36 hours printing. Although I am sure that pro photographers with large budgets and assistants did just that.But honestly these gadgets ONLY get in the way of what you should be doing, putting hopeful negatives in the enlarger and giving them a try because you are taking "time" away from the darkroom, and the impression of whether or not a particular negative will make a good print is fleeting.