Constant BLE 

pub const BLE: u32 = 50;

CAP_BLE — the device has a Bluetooth transport whose reachability it can turn on and off (PROP_BLE_ENABLED, PROP_BLE_LINK). It says nothing about the stack underneath, and in particular does not promise that clearing PROP_BLE_ENABLED powers a radio down.

The only Bluetooth capability there is. What else a given transport will do — manage its own bonds, hold a pairing PIN — a host learns by asking for the property or sending the command and reading the refusal, which is a question it has to be able to answer anyway.