But does it have to take up that much space? They used a pretty small module in the iPod Nano 6G, almost no bigger than to wrap around the headphone jack. Unless there is something that I'm missing, there doesn't seem to be any reason for it to be so big asides from stability (the iPod's own casing probably helps hold its module in place)Have you ever repaired a phone and taken a look at the internals of said phone? The 3.5 mm jack takes up a massive amount of real estate inside the hardware of the device, space that was replaced with a larger battery, larger taptic engine, etc.
iPhone 6S/Nano 6G comparison: