I've personally designed miner boxes from cooler boxes for the various ASICs I operate  (L3+, etc.), and I've found they all work well as long as you have a way to ventilate the air the miners create, and you monitor temperatures as needed so you can add fans to increase intake or exhaust or up fan RPM so the miners don't overheat. I've seen people design miner boxes that twist around apparently to trap sound and to allow air to flow, but in reality those designs restrict airflow too much to be useful. Always make sure to test what you make over an extended period of time to ensure your design can work 24/7.