Do not hardcode address zero (address(0)) as zroPaymentAddress when estimating fees and sending messages. Pass it as a parameter instead.
File: src/RootBridgeAgent.sol
823:             ILayerZeroEndpoint(lzEndpointAddress).send{value: msg.value}(
824:                 _dstChainId,
825:                 getBranchBridgeAgentPath[_dstChainId],
826:                 _payload,
827:                 _refundee,
828:                 address(0),
829:                 abi.encodePacked(uint16(2), _gParams.gasLimit, _gParams.remoteBranchExecutionGas, callee)
830:             );
File: BranchBridgeAgent.sol
768:     function _performCall(address payable _refundee, bytes memory _payload, GasParams calldata _gParams)
769:         internal
770:         virtual
771:     {
772:         //Sends message to LayerZero messaging layer
773:         ILayerZeroEndpoint(lzEndpointAddress).send{value: msg.value}(
774:             rootChainId,
775:             rootBridgeAgentPath,
776:             _payload,
777:             payable(_refundee),
778:             address(0),//@audit Integration issue - Do not hardcode address 0 as it may cause future upgrades difficulty
779:             abi.encodePacked(uint16(2), _gParams.gasLimit, _gParams.remoteBranchExecutionGas, rootBridgeAgentAddress)
780:         );
781:     }
