Allow cancelling (clearing) chracteristic writes for Bluetooth Low Energy

This is a suggestion request for the ability to cancel a queued write to a characteristic for a Bluetooth Low Energy service. If you queue up a write of say 150 bytes, it goes out as multiple packets but after 1 or 2 have been sent there may be a reason to want to cancel the rest (and know exactly how much has been sent) which is not currently possible.