There are some potential feefilter cleanups mentioned and motivated in comment https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-805808485 . If you address the locking one, please be careful and make sure that `round()` is only called under a lock. See https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-807992199

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if (args.SoftSetBoolArg("-upnp", false))
            LogPrintf("%s: parameter interaction: -proxy set -> setting -upnp=0\n", __func__);
        if (args.SoftSetBoolArg("-natpmp", false)) {
            LogPrintf("%s: parameter interaction: -proxy set -> setting -natpmp=0\n", __func__);
        }
        
        if (args.SoftSetBoolArg("-discover", false))
            LogPrintf("%s: parameter interaction: -proxy set -> setting -discover=0\n", __func__);
    }
    if (!args.GetBoolArg("-listen", DEFAULT_LISTEN)) {
        
        if (args.SoftSetBoolArg("-upnp", false))
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -upnp=0\n", __func__);
        if (args.SoftSetBoolArg("-natpmp", false)) {
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -natpmp=0\n", __func__);
        }
        if (args.SoftSetBoolArg("-discover", false))
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -discover=0\n", __func__);
        if (args.SoftSetBoolArg("-listenonion", false))
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -listenonion=0\n", __func__);
        if (args.SoftSetBoolArg("-i2pacceptincoming", false)) {
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -i2pacceptincoming=0\n", __func__);
        }
    }
    if (args.IsArgSet("-externalip")) {
        
        if (args.SoftSetBoolArg("-discover", false))
            LogPrintf("%s: parameter interaction: -externalip set -> setting -discover=0\n", __func__);
    }