Is it possible (and does it make sense) to have a

We are currently building a device that needs to be compatible with newer smartphones that run BLE but also be backwards compatible with Bluetooth 2.1.

We are using a Mediatek Linkit ONE board for our prototype which can operate in dual mode. They have Bluetooth classes available, however it seems that I would have to pick between either running 1) Bluetooth Classic 2.1 OR 2) BLE

The classes and docs are here: http://labs.mediatek.com/site/znch/developer_tools/mediatek_linkit/api_references/Lib_Bluetooth.gsp

We basically want to make our device compatible with as many Smart phones as possible so I wonder whether it possible to have a device that is a peripheral to listen to both, BLE and Bluetooth Classic Connections at the same time. Then if it gets connected to via either, stop broadcasting the other?

The only technical way seems to have maybe a dip switch on the iot device that sets the mode and it uses BLE code base or Classic code base based on the position of the dip switch. That does not seem very elegant to me.

Lastly, I wonder if my question even makes sense. I searched around for hours and I cannot seem to find anybody else that is doing this, so I wonder if most people are just going with BLE these days and just don't care about about Classic BR/EDR anymore. Any help would be much appreciated.

We basically want to make our device compatible with as many Smart phones as possible so I wonder whether it possible to have a device that is a peripheral to listen to both, BLE and Bluetooth Classic Connections at the same time

With LinkIt ONE HDK/SDK, the above scenario is achievable. The Bluetooth 2.1 and Bluetooth GATT (4.0) on LinkIt ONE platform run independently. Currently, the LinkIt ONE platform supports SPP (2.1) and GATT (4.0) profiles. You can start to try both the SPP and GATT at the same time on the board, by instantiating the objects of BT Basic and BLE separately.