matomo delay in content impression

Question

I'm trying to track some content with Matomo's tracking-client.

After initializing the client my snippet is like this:

window.matomoAsyncInit = function () {

        console.log('track start');

        try {
            var contentTracker = Matomo.getTracker('...Host...', '...');
            contentTracker.trackAllContentImpressions();
        } catch( err ) {}
    };

Everything works well except for a timeout of 3 seconds between the log-message 'track start' and the request to matomo-server. Is there any configuration or option to reduce this delay?