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.

{
    string strStatusBar;
    string strRPC;
    string strGUI;
    if (!CLIENT_VERSION_IS_RELEASE) {
        strStatusBar = "This is a pre-release test build - use at your own risk - do not use for mining or merchant applications";
        strGUI = _("This is a pre-release test build - use at your own risk - do not use for mining or merchant applications");
    }
    if (GetBoolArg("-testsafemode", DEFAULT_TESTSAFEMODE))
        strStatusBar = strRPC = strGUI = "testsafemode enabled";
    
    if (strMiscWarning != "")
    {
        strStatusBar = strGUI = strMiscWarning;
    }
    if (fLargeWorkForkFound)
    {
        strStatusBar = strRPC = "Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.";
        strGUI = _("Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.");
    }
    else if (fLargeWorkInvalidChainFound)
    {
        strStatusBar = strRPC = "Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.";
        strGUI = _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.");
    }
    if (strFor == "gui")