One of the features of Bluetooth v4.1 is the ability to exchange BLE data at the L2CAP layer. The L2CAP layer is lower than the GATT layer which will result in higher throughput of data exchange. I was wondering is there any Stack/OS that has exposed this feature (especially BlueZ/Android/iOS)?
iOS does support L2CAP CO with iOS 10.2+ - see https://developer.apple.com/documentation/corebluetooth/cbl2capchannel
Android doesn't support this as far as i could test. I'm still waiting for that feature....
UPDATE: Removed wrong link