Gimbal devices in their default proprietary mode are incompatible with CoreLocation APIs. Simply put, they are not iBeacons at all.
They can only be detected with CoreBluetooth which has entirely different rules about background usage. Reading the identifiers is impossible without Qualcomm's proprietary SDK.
The CoreLocation improvements in iOS 7.1 therefore offer no benefit for out-of-the-box Gimbal beacons. To get the benefit, you have to jailbreak them to make them standard iBeacons.
Full disclosure: I am Chief Engineer for Radius Networks