My first boss out of college always said “There comes a point in every project where you have to shoot the engineer.” A bit harsh, perhaps. And just to be clear, he never actually did that to my knowledge. The point was well taken and I have made an effort during my career to focus on the business case for the project, not just the engineering perspective.
Rather than shooting them, I have a better suggestion: distract them with the next shiny engineering challenge. Buy them a dev kit from SparkFun so they can play around with something new. Or ask them if they know anything about ______ (literally any piece of technology). That should keep them busy long enough for you to ship your product.