I don't yet have a use for Bluetooth, but I do have a few BLE buttons laying around (they're dirt cheap and last years on a single battery), and I can see e.g. having a dedicated button per temp (or perhaps to switch calibration profiles for different tips) could be useful if I did a lot of soldering.
It's minor stuff, not playing Doom while using motion controls. Hiding this kind of control in a proprietary dongle (i.e. the base) is much worse than it being programmable.