There are some potential feefilter cleanups mentioned and motivated in comment https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-805808485 . If you address the locking one, please be careful and make sure that `round()` is only called under a lock. See https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-807992199

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UnregisterValidationInterface(g_zmq_notification_interface);
        delete g_zmq_notification_interface;
        g_zmq_notification_interface = nullptr;
    }
#endif
    node.chain_clients.clear();
    UnregisterAllValidationInterfaces();
    GetMainSignals().UnregisterBackgroundSignalScheduler();
    init::UnsetGlobals();
    node.mempool.reset();
    node.fee_estimator.reset();
    node.chainman = nullptr;
    node.scheduler.reset();
    try {
        if (!fs::remove(GetPidFile(*node.args))) {
            LogPrintf("%s: Unable to remove PID file: File does not exist\n", __func__);
        }
    } catch (const fs::filesystem_error& e) {
        LogPrintf("%s: Unable to remove PID file: %s\n", __func__, fsbridge::get_filesystem_error_message(e));
    }
    node.args = nullptr;
    LogPrintf("%s: done\n", __func__);
}
/**
 * Signal handlers are very limited in what they are allowed to do.
 * The execution context the handler is invoked in is not guaranteed,
 * so we restrict handler operations to just touching variables:
 */
#ifndef WIN32
static void HandleSIGTERM(int)