in v0.12 https://github.com/bitcoin/bitcoin/pull/7081 (by @luke-jr) was merged adding `-bytespersigop` (with default of 20).

this is preventing simple bare multisig transactions from being accepted into mempool when the size is < 400 bytes.  
eg; https://gist.github.com/rubensayshi/ac4f617207f7a50559e85d61c05800be

from 1-of-7 and onwards they are accepted because the ratio of bytes:sigops is high enough.  
also having 2 or more inputs will work because it again tips the ratio of bytes:sigops over.

the reason mainly being that `GetLegacySigOpCount` calls `GetSigOpCount` with `fAccurate=false`.

It looks like changing `GetLegacySigOpCount` to use `fAccurate=true` would cause side effects in the few other places (`ConnectBlock`, `CheckBlock`, `CreateNewBlock`) and simply adding `fAccurate` as arg to `GetLegacySigOpCount` would affect the value stored in `CTxMemPoolEntry.sigOpCount` which in turn affects a bunch of other things.

{
        uiInterface.InitMessage.connect(SetRPCWarmupStatus);
        if (!AppInitServers(threadGroup))
            return InitError(_("Unable to start HTTP server. See debug log for details."));
    }
    int64_t nStart;
    
#ifdef ENABLE_WALLET
    if (!fDisableWallet) {
        if (!CWallet::Verify())
            return false;
    } 
#endif 
    
    RegisterNodeSignals(GetNodeSignals());
    
    std::vector<string> uacomments;
    BOOST_FOREACH(string cmt, mapMultiArgs["-uacomment"])
    {
        if (cmt != SanitizeString(cmt, SAFE_CHARS_UA_COMMENT))
            return InitError(strprintf(_("User Agent comment (%s) contains unsafe characters."), cmt));
        uacomments.push_back(SanitizeString(cmt, SAFE_CHARS_UA_COMMENT));
    }
    strSubVersion = FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, uacomments);
    if (strSubVersion.size() > MAX_SUBVERSION_LENGTH) {
        return InitError(strprintf(_("Total length of network version string (%i) exceeds maximum length (%i). Reduce the number or size of uacomments."),
            strSubVersion.size(), MAX_SUBVERSION_LENGTH));
    }
    if (mapArgs.count("-onlynet")) {
        std::set<enum Network> nets;