In the log I see things like:

    2017-09-13 03:54:33 init message: Rescanning...
    2017-09-13 03:54:33 Rescanning last 68616 blocks (from block 416339)...
    2017-09-13 03:54:40 AddToWallet xxxxx  update
    2017-09-13 03:55:33 Still rescanning. At block 418849. Progress=0.549138

I would be interested to see the wallet file name on each of these log lines.

Would there be any interest in merging such a PR?
{
    AssertLockHeld(cs_main);
    AssertLockHeld(cs_wallet);
    vCoins.clear();
    CAmount nTotal = 0;
    for (const auto& entry : mapWallet)
    {
        const uint256& wtxid = entry.first;
        const CWalletTx* pcoin = &entry.second;
        if (!CheckFinalTx(*pcoin->tx))
            continue;
        if (pcoin->IsCoinBase() && pcoin->GetBlocksToMaturity() > 0)
            continue;
        int nDepth = pcoin->GetDepthInMainChain();
        if (nDepth < 0)
            continue;
        
        
        if (nDepth == 0 && !pcoin->InMempool())
            continue;
        bool safeTx = pcoin->IsTrusted();