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.

} else {
            
            bPingFinished = true;
            sProblem = "Short payload";
        }
        if (!(sProblem.empty())) {
            LogPrint("net", "pong peer=%d: %s, %x expected, %x received, %u bytes\n",
                pfrom->id,
                sProblem,
                pfrom->nPingNonceSent,
                nonce,
                nAvail);
        }
        if (bPingFinished) {
            pfrom->nPingNonceSent = 0;
        }
    }
    else if (strCommand == NetMsgType::FILTERLOAD)
    {
        CBloomFilter filter;
        vRecv >> filter;
        LOCK(pfrom->cs_filter);
        if (!filter.IsWithinSizeConstraints())
        {
            
            LOCK(cs_main);
            Misbehaving(pfrom->GetId(), 100);
        }
        else
        {