For software that interfaces with Bitcoin Core via RPC, it can be useful to know whether the fRelayTxes flag is set. It could be added to `getnetworkinfo`.

try {
            CBlock &block = const_cast<CBlock&>(chainparams.GenesisBlock());
            
            unsigned int nBlockSize = ::GetSerializeSize(block, SER_DISK, CLIENT_VERSION);
            CDiskBlockPos blockPos;
            CValidationState state;
            if (!FindBlockPos(state, blockPos, nBlockSize+8, 0, block.GetBlockTime()))
                return error("LoadBlockIndex(): FindBlockPos failed");
            if (!WriteBlockToDisk(block, blockPos, chainparams.MessageStart()))
                return error("LoadBlockIndex(): writing genesis block to disk failed");
            CBlockIndex *pindex = AddToBlockIndex(block);
            if (!ReceivedBlockTransactions(block, state, pindex, blockPos))
                return error("LoadBlockIndex(): genesis block not accepted");
            if (!ActivateBestChain(state, chainparams, &block))
                return error("LoadBlockIndex(): genesis block cannot be activated");
            
            return FlushStateToDisk(state, FLUSH_STATE_ALWAYS);
        } catch (const std::runtime_error& e) {
            return error("LoadBlockIndex(): failed to initialize block database: %s", e.what());
        }
    }
    return true;
}
bool LoadExternalBlockFile(const CChainParams& chainparams, FILE* fileIn, CDiskBlockPos *dbp)
{
    
    static std::multimap<uint256, CDiskBlockPos> mapBlocksUnknownParent;
    int64_t nStart = GetTimeMillis();
    int nLoaded = 0;
    try {