EDITED 2019-02-08

`maxTxFee` is a global variable, used by both the raw transaction and wallet RPCs. It's set from `-maxtxfee`.

~listed in the global help text in init.cpp, but is only set in `WalletInit::ParameterInteraction()`. If the wallet is disabled, then `-maxtxfee` is ignored and the default is used.~

~This behaviour has existed since the mempool was changed to limit acceptance based on `maxTxFee` in https://github.com/bitcoin/bitcoin/commit/fa331db68bcc68e4c93fb45aaa30f911b0ecfe1a.~

~Short-term fix is to move the `-maxtxfee` handling to `InitParameterInteraction()` in init.cpp.~
EDIT: `maxTxFee` initiation bug fixed in #15357 

I don't think we should share this setting between the node and wallet.
connOptions.nMaxAddnode = MAX_ADDNODE_CONNECTIONS;
    connOptions.nMaxFeeler = 1;
    connOptions.nBestHeight = chain_active_height;
    connOptions.uiInterface = &uiInterface;
    connOptions.m_banman = g_banman.get();
    connOptions.m_msgproc = peerLogic.get();
    connOptions.nSendBufferMaxSize = 1000*gArgs.GetArg("-maxsendbuffer", DEFAULT_MAXSENDBUFFER);
    connOptions.nReceiveFloodSize = 1000*gArgs.GetArg("-maxreceivebuffer", DEFAULT_MAXRECEIVEBUFFER);
    connOptions.m_added_nodes = gArgs.GetArgs("-addnode");
    connOptions.nMaxOutboundTimeframe = nMaxOutboundTimeframe;
    connOptions.nMaxOutboundLimit = nMaxOutboundLimit;
    connOptions.m_peer_connect_timeout = peer_connect_timeout;
    for (const std::string& strBind : gArgs.GetArgs("-bind")) {
        CService addrBind;
        if (!Lookup(strBind.c_str(), addrBind, GetListenPort(), false)) {
            return InitError(ResolveErrMsg("bind", strBind));
        }
        connOptions.vBinds.push_back(addrBind);
    }
    for (const std::string& strBind : gArgs.GetArgs("-whitebind")) {
        CService addrBind;
        if (!Lookup(strBind.c_str(), addrBind, 0, false)) {
            return InitError(ResolveErrMsg("whitebind", strBind));
        }
        if (addrBind.GetPort() == 0) {
            return InitError(strprintf(_("Need to specify a port with -whitebind: '%s'"), strBind));
        }
        connOptions.vWhiteBinds.push_back(addrBind);
    }
    for (const auto& net : gArgs.GetArgs("-whitelist")) {