The function getDeploymentBlock() present in the Holographer contract returns an address, while everything indicates that the underlying value holds a uint256 that represents a block number, and even the function is named after that. This is caused because the contract uses unstructured storage and the slot value is sloaded directly into an address type, and could make integrations with this code fail, or even truncate the returned value since the address type is 20 bytes long.
The error is also present in the interface HolographerInterface.
The return type in the contract and interface should be changed to uint256.