Modifying the Mac mini by CNC machining a large opening at the top of the case and replacing it with a perspex cover could potentially improve Bluetooth connectivity, but it's not a guaranteed solution, and there are several factors to consider. The thick alloy case of the Mac mini can indeed interfere with Bluetooth signals to some extent, as metal can block or reflect wireless signals. Creating an opening and replacing it with a transparent material like perspex (acrylic) can allow Bluetooth signals to pass more freely, potentially enhancing connectivity. However, it's important to keep in mind the following: (1) Warranty and Risk: Modifying your Mac mini in this way may void your warranty. Apple typically doesn't support or endorse such modifications, and you risk damaging the device if not done correctly. (2) Skill and Precision: CNC machining requires skill and precision. If not done accurately, it could damage the Mac mini or compromise its structural integrity. (3) Other Interference: Bluetooth...