Hello again …
external tasks are imho not just another way of implementing a message queue. They are an inversion of control, anew way of thinking how external services interact with your process.
You would not notify an external worker that a task is active. You would just wait until a worker comes by (possible scheduled) and executes it. Think of “tasklist for services”.
I am not saying that this is the “new way” to go, it is a new approach to a certain kind of problem. If you require tight interaction, direct feedback, no waittime and full control on the process side, the external worker is not for you. If you can deal with “I am loosly coupled, resilient and my external task will eventually be completed if I just sit and wait”, it’s perfect.
Jan