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?
LOCK2(cs_main, cs_wallet);
    for (const CTransactionRef& ptx : pblock->vtx) {
        SyncTransaction(ptx);
    }
}
void CWallet::BlockUntilSyncedToCurrentChain() {
    AssertLockNotHeld(cs_main);
    AssertLockNotHeld(cs_wallet);
    {
        
        
        
        
        
        LOCK(cs_main);
        const CBlockIndex* initialChainTip = chainActive.Tip();
        if (m_last_block_processed && m_last_block_processed->GetAncestor(initialChainTip->nHeight) == initialChainTip) {
            return;
        }
    }
    
    
    
    SyncWithValidationInterfaceQueue();
}
isminetype CWallet::IsMine(const CTxIn &txin) const