I can’t directly answer the question, as I don’t use one. But I would like to mention that I put on a pair of joystick caps which are frankly pretty thin layers of silicon all things considered, and now the Deck won’t fit inside the case unless I firmly close hold it closed and then pull the zipper.

The case is designed to fit it very snugly, it would seem! But third-party based usually have more give inside for covers and joystick caps etc.