Tasks are never created:

EngineRunTaskPerform is just a task performer and not an engine. It requires dvce-app-config.xml with the EngineRun entry in it. This entry has to be in the file. On boot up, the server will then know to create a listener for this task. Without this entry, then no listener will be created. No listener means NO engine will ever create Tasks.

Task Generator or Writer Spikes the App Server or Database

The logic in the Task Generator or Writer is limited to the one App Server and the Database. There is no possibility for horizontal or vertical scalability. If you have to create 400,000 tasks (1 per item and 400,000 items), then you have to have 1 App Server and the Database dedicated to inserting those records.