Chosen Solution
I have my Mac With Continuity and a USB Bluetooth Device, but can I internally change the bluetooth to 4.0? Is there and upgraded replacement for it?
If you review this IFIXIT guide: MacBook Unibody Model A1342 AirPort/Bluetooth Board Replacement Sadly the AirPort card (WiFi/Bluetooth) is unique in this series. Broadcom never offered a compatible upgrade part for either WiFi 802.11ac or Bluetooth 4.x. Your only option is to use the external USB Bluetooth adapter.
