I want to set the title so that it will come over the video clip (30 min) after 10 minutes (600000ms). Unfortunately, Delay only allows a delay of up to 30 seconds, despite the setting of 600000ms. Is it possible to do?

If you want to create a longer delay and are prepared to live with the risk of odd consequences, you can set a trigger to Set Volume of the Input to 100% (where it probably is anyway) after 30,000 milliseconds, and then put another trigger with a delay of <30,000 milliseconds, or if you need to, repeat the Set Volume trigger. In the first instance, the 'real' trigger will activate after 30,000 + however many milliseconds you specify. If you keep adding 30,000 millisecond fake delays, remember that you may get odd, unexpected triggers occurring later on.