Whenever -blocksonly is specified, there is implicitly a zero size mempool. However, there is still a non-zero value for -maxmempool which will be shared with dbcache, leading to 300 MB extra usage. Fix this.
argsman.AddArg("-rpcworkqueue=<n>", strprintf("Set the depth of the work queue to service RPC calls (default: %d)", DEFAULT_HTTP_WORKQUEUE), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::RPC);
    argsman.AddArg("-server", "Accept command line and JSON-RPC commands", ArgsManager::ALLOW_ANY, OptionsCategory::RPC);
#if HAVE_DECL_FORK
    argsman.AddArg("-daemon", strprintf("Run in the background as a daemon and accept commands (default: %d)", DEFAULT_DAEMON), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-daemonwait", strprintf("Wait for initialization to be finished before exiting. This implies -daemon (default: %d)", DEFAULT_DAEMONWAIT), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#else
    hidden_args.emplace_back("-daemon");
    hidden_args.emplace_back("-daemonwait");
#endif
#if defined(USE_SYSCALL_SANDBOX)
    argsman.AddArg("-sandbox=<mode>", "Use the experimental syscall sandbox in the specified mode (-sandbox=log-and-abort or -sandbox=abort). Allow only expected syscalls to be used by bitcoind. Note that this is an experimental new feature that may cause bitcoind to exit or crash unexpectedly: use with caution. In the \"log-and-abort\" mode the invocation of an unexpected syscall results in a debug handler being invoked which will log the incident and terminate the program (without executing the unexpected syscall). In the \"abort\" mode the invocation of an unexpected syscall results in the entire process being killed immediately by the kernel without executing the unexpected syscall.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#endif 
    
    argsman.AddHiddenArgs(hidden_args);
}
static bool fHaveGenesis = false;
static GlobalMutex g_genesis_wait_mutex;
static std::condition_variable g_genesis_wait_cv;
static void BlockNotifyGenesisWait(const CBlockIndex* pBlockIndex)
{
    if (pBlockIndex != nullptr) {
        {
            LOCK(g_genesis_wait_mutex);
            fHaveGenesis = true;
        }
        g_genesis_wait_cv.notify_all();
    }
}
#if HAVE_SYSTEM
static void StartupNotify(const ArgsManager& args)