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?
CPubKey seed = walletInstance->GenerateNewSeed();
            walletInstance->SetHDSeed(seed);
        }
        
        if (!walletInstance->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) && !walletInstance->TopUpKeyPool()) {
            InitError(_("Unable to generate initial keys"));
            return nullptr;
        }
        walletInstance->ChainStateFlushed(chainActive.GetLocator());
    } else if (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS) {
        
        InitError(strprintf(_("Error loading %s: Private keys can only be disabled during creation"), walletFile));
        return NULL;
    } else if (walletInstance->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
        LOCK(walletInstance->cs_KeyStore);
        if (!walletInstance->mapKeys.empty() || !walletInstance->mapCryptedKeys.empty()) {
            InitWarning(strprintf(_("Warning: Private keys detected in wallet {%s} with disabled private keys"), walletFile));
        }
    } else if (gArgs.IsArgSet("-usehd")) {
        bool useHD = gArgs.GetBoolArg("-usehd", true);
        if (walletInstance->IsHDEnabled() && !useHD) {
            InitError(strprintf(_("Error loading %s: You can't disable HD on an already existing HD wallet"), walletFile));
            return nullptr;
        }
        if (!walletInstance->IsHDEnabled() && useHD) {
            InitError(strprintf(_("Error loading %s: You can't enable HD on an already existing non-HD wallet"), walletFile));
            return nullptr;
        }
    }