You are able to access to Eddystone, iBeacon and Global Services from the GATT table. Take into account that each characteristic has its own lock requirement so that, unless the beacon is unlocked, you won’t be able to read/write all the characteristics.
Moreover, remember that for Eddystone EID slot, the beacon does not have the real ID saved in so that you will just read the encrypted ID.
For further information, check iBKS GATT Reference Manual from Developers area through our Support Center.